chore: v2.8.45 — Share again updates a shared skill; a same-named upload updates it too

A shared skill followed its owner's ~/.claude/skills folder only, so one
uploaded from a browser (or living in a plugin) stayed at its first snapshot
for good. Share again (a skill's ⋯ menu and detail sheet) now takes the
owner's copy on the server — its source folder, else the same-named skill of
a plugin they installed at user scope — and shares it; with no copy it asks
for the folder and uploads it onto that row (`id`). An upload whose skill is
named like one the uploader already has replaces that row's version instead
of adding a twin. Installers are then offered Update, as before.

client/src/components/lanes/LaneChangesPanel.tsx

@@ -1470,25 +1470,40 @@ export function LaneChangesPanel({
     }
   };
 
-  // Discard all: every non-conflicted file in one `discard`, asked once in a
-  // dialog that names how many untracked files it will delete.
-  const discardAll = async () => {
-    const rows = files.filter((f) => !f.conflicted);
-    if (!rows.length) return;
+  // Discard selected: exactly what Commit would take — the ticked files, and
+  // only the ticked blocks of a partly ticked one (#87: it used to discard
+  // every file, ticked or not) — in one `discard`, asked once in a dialog
+  // that names how many untracked files it will delete.
+  const discardTicked = async () => {
+    if (!tickedPaths.length) return;
     const ok = await confirmDialog({
-      title: t("changes.discardAllTitle"),
-      message: t("changes.discardAllConfirm", {
-        count: rows.length,
-        untracked: rows.filter((f) => f.untracked).length,
+      title: t("changes.discardTickedTitle"),
+      message: t("changes.discardTickedConfirm", {
+        count: tickedPaths.length,
+        untracked: files.filter((f) => f.untracked && tickedPaths.includes(f.path)).length,
       }),
-      confirmLabel: t("changes.discardAll"),
+      confirmLabel: t("changes.discardTicked"),
     });
-    if (ok)
-      await act(
-        "discard",
-        rows.map((f) => f.path),
-        true
-      );
+    if (!ok) return;
+    const lane = laneId;
+    setBusy(true);
+    setError(null);
+    try {
+      const { paths, hunks } = await selection();
+      await api.lanes.gitAction(target, "discard", {
+        paths,
+        ...(hunks ? { hunks, context: CONTEXT_STEPS[0] } : {}),
+        confirm: true,
+      });
+      if (laneNow.current !== lane) return;
+      setConfirmDiscard(null);
+      refreshGit();
+      await load();
+    } catch (err) {
+      if (laneNow.current === lane) setError(err instanceof Error ? err.message : String(err));
+    } finally {
+      if (laneNow.current === lane) setBusy(false);
+    }
   };
 
   // resolve / merge-commit / merge-abort: same shape as `act`, other body.
@@ -2067,8 +2082,7 @@ export function LaneChangesPanel({
   // An HTML page's relative CSS/scripts/images, read like a download — only
   // from the working tree: a commit's page would get today's files.
   const htmlFetch = useMemo(
-    () =>
-      range === "commit" ? null : fetchVia((p) => api.lanes.gitDownloadUrl(target, p)),
+    () => (range === "commit" ? null : fetchVia((p) => api.lanes.gitDownloadUrl(target, p))),
     // eslint-disable-next-line react-hooks/exhaustive-deps
     [range, JSON.stringify(target)]
   );
@@ -2863,13 +2877,13 @@ export function LaneChangesPanel({
                     <button
                       type="button"
                       data-testid="lane-changes-discard-all"
-                      disabled={busy}
-                      onClick={() => void discardAll()}
-                      title={t("changes.discardAllTitle")}
+                      disabled={busy || tickedPaths.length === 0}
+                      onClick={() => void discardTicked()}
+                      title={t("changes.discardTickedTitle")}
                       className="shrink-0 flex items-center gap-1 rounded border border-border-light px-1.5 py-0.5 text-[11px] text-status-danger hover:bg-status-danger/10 disabled:cursor-not-allowed disabled:opacity-40"
                     >
                       <Trash2 className="h-3 w-3" aria-hidden />
-                      {t("changes.discardAll")}
+                      {t("changes.discardTicked", { count: tickedPaths.length })}
                     </button>
                   </div>
                 </div>

client/src/components/lanes/__tests__/LaneChangesPanel.test.tsx

@@ -837,10 +837,12 @@ describe("LaneChangesPanel", () => {
     });
   });
 
-  it("discards every file at once only after the dialog is confirmed", async () => {
+  it("discards only the ticked files, and only after the dialog is confirmed (#87)", async () => {
     const user = userEvent.setup();
     render(<LaneChangesPanel laneId={7} />);
     await screen.findByTestId("lane-changes-overview");
+    // notes.txt (unversioned) starts unticked; untick docs/API.md too.
+    await user.click(tickOf("docs/API.md"));
 
     vi.mocked(confirmDialog).mockResolvedValueOnce(false);
     await user.click(screen.getByTestId("lane-changes-discard-all"));
@@ -849,10 +851,14 @@ describe("LaneChangesPanel", () => {
     await user.click(screen.getByTestId("lane-changes-discard-all"));
     await waitFor(() =>
       expect(api.lanes.gitAction).toHaveBeenCalledWith(7, "discard", {
-        paths: ["server/lib/git-ops.js", "notes.txt", "docs/API.md"],
+        paths: ["server/lib/git-ops.js"],
         confirm: true,
       })
     );
+
+    // Nothing ticked: nothing to discard.
+    await user.click(tickOf("server/lib/git-ops.js"));
+    expect(screen.getByTestId("lane-changes-discard-all")).toBeDisabled();
   });
 
   it("right-click on a changed file offers Commit File, a two-click discard, copy path and patch", async () => {
@@ -1673,6 +1679,25 @@ describe("LaneChangesPanel", () => {
       expect(api.lanes.gitAction).not.toHaveBeenCalled();
     });
 
+    it("discards only the ticked change blocks of a partly ticked file (#87)", async () => {
+      const user = userEvent.setup();
+      await openReview(user);
+      await user.click(
+        screen.getAllByRole("checkbox", { name: "Include this change in the commit" })[1]!
+      );
+      await user.click(screen.getByRole("button", { name: "Changes" }));
+      await screen.findByTestId("lane-changes-commit");
+      await user.click(screen.getByTestId("lane-changes-discard-all"));
+      await waitFor(() =>
+        expect(api.lanes.gitAction).toHaveBeenCalledWith(7, "discard", {
+          paths: [],
+          hunks: { "server/lib/git-ops.js": [{ hunk: "@@ -1,2 +1,3 @@", blocks: [0] }] },
+          context: 3,
+          confirm: true,
+        })
+      );
+    });
+
     it("commits only the ticked change blocks of a partly ticked file (hunks)", async () => {
       const user = userEvent.setup();
       await openReview(user);

client/src/i18n/locales/en/artifacts.json

@@ -28,6 +28,12 @@
   "unshare": "Unshare",
   "shareDone": "Shared to the Hub",
   "unshareDone": "Removed from the Hub",
+  "reshare": "Share again",
+  "reshareDone": "New version shared — people who installed it are offered Update",
+  "reshareSame": "Already the newest version — shared",
+  "reshareAskTitle": "Choose the {{name}} folder again",
+  "reshareAskBody": "This server has no copy of {{name}}. Choose the skill's folder (the one holding SKILL.md): it replaces this version, and people who installed it are offered Update. For a .zip, upload it through Add skill → Upload: a skill with the same name updates your existing one.",
+  "resharePick": "Choose folder",
   "open": "Open",
   "copyLink": "Copy link",
   "preview": "Preview",

client/src/i18n/locales/en/lanes.json

@@ -532,9 +532,9 @@
   "changes.unversionedGroup": "Unversioned Files",
   "changes.commitTicked": "Commit ({{count}})",
   "changes.commitAndPush": "Commit and Push",
-  "changes.discardAll": "Discard all",
-  "changes.discardAllTitle": "Discard all changes?",
-  "changes.discardAllConfirm": "Every change in {{count}} file(s) goes back to the last commit, and {{untracked}} new file(s) git does not track yet are deleted. This cannot be undone.",
+  "changes.discardTicked": "Discard ({{count}})",
+  "changes.discardTickedTitle": "Discard the ticked changes?",
+  "changes.discardTickedConfirm": "The ticked changes in {{count}} file(s) go back to the last commit, and {{untracked}} ticked new file(s) git does not track yet are deleted. Unticked files and blocks are kept. This cannot be undone.",
   "changes.amendAndPush": "Amend and Push",
   "changes.pushFailed": "Committed, but the push failed: {{error}}",
   "changes.tickFile": "Include {{path}} in the commit",

client/src/i18n/locales/vi/artifacts.json

@@ -28,6 +28,12 @@
   "unshare": "Bỏ chia sẻ",
   "shareDone": "Đã chia sẻ lên Hub",
   "unshareDone": "Đã gỡ khỏi Hub",
+  "reshare": "Share lại",
+  "reshareDone": "Đã share bản mới — người đã cài sẽ thấy nút Cập nhật",
+  "reshareSame": "Đã là bản mới nhất — đã share",
+  "reshareAskTitle": "Chọn lại thư mục {{name}}",
+  "reshareAskBody": "Server không có bản của {{name}}. Chọn thư mục của skill (thư mục chứa SKILL.md): bản này sẽ được thay, và người đã cài sẽ thấy nút Cập nhật. Với file .zip, tải lên qua Thêm skill → Tải lên: skill trùng tên sẽ cập nhật mục bạn đã có.",
+  "resharePick": "Chọn thư mục",
   "open": "Mở",
   "copyLink": "Sao chép link",
   "preview": "Xem",

client/src/i18n/locales/vi/lanes.json

@@ -532,9 +532,9 @@
   "changes.unversionedGroup": "File chưa theo dõi",
   "changes.commitTicked": "Commit ({{count}})",
   "changes.commitAndPush": "Commit và Push",
-  "changes.discardAll": "Bỏ tất cả",
-  "changes.discardAllTitle": "Bỏ tất cả thay đổi?",
-  "changes.discardAllConfirm": "Mọi thay đổi trong {{count}} file sẽ trở về commit cuối, và {{untracked}} file mới chưa được git theo dõi sẽ bị xoá. Không thể hoàn tác.",
+  "changes.discardTicked": "Bỏ ({{count}})",
+  "changes.discardTickedTitle": "Bỏ các thay đổi đã chọn?",
+  "changes.discardTickedConfirm": "Các thay đổi đã chọn trong {{count}} file sẽ trở về commit cuối, và {{untracked}} file mới đã chọn chưa được git theo dõi sẽ bị xoá. File và đoạn không chọn được giữ nguyên. Không thể hoàn tác.",
   "changes.amendAndPush": "Amend và Push",
   "changes.pushFailed": "Đã commit, nhưng push thất bại: {{error}}",
   "changes.tickFile": "Đưa {{path}} vào commit",

client/src/lib/api.ts

@@ -3324,16 +3324,17 @@ export const api = {
      *  several skills at once (one artifact each). `path` keeps a folder's layout. */
     uploadSkills: (
       files: { file: File; path: string }[],
-      fields: { name?: string; title?: string; description?: string } = {}
+      /** `id`: Share again — the upload replaces that skill row's version. */
+      fields: { name?: string; title?: string; description?: string; id?: string } = {}
     ) => {
       const form = new FormData();
       for (const f of files) form.append("files", f.file, f.file.name);
       form.append("paths", JSON.stringify(files.map((f) => f.path)));
       for (const [k, v] of Object.entries(fields)) if (v) form.append(k, v);
-      return request<{ items: Artifact[] }>("/artifacts/skill/upload", {
-        method: "POST",
-        body: form,
-      });
+      return request<{ items: (Artifact & { replaced?: boolean; changed?: boolean })[] }>(
+        "/artifacts/skill/upload",
+        { method: "POST", body: form }
+      );
     },
     /** One file from the user's computer, kept like a pinned one (≤ 25 MB). */
     uploadFile: (file: File, fields: { title?: string; description?: string } = {}) => {
@@ -3372,6 +3373,12 @@ export const api = {
         method: "PATCH",
         body: JSON.stringify(body),
       }),
+    /** POST /api/artifacts/:id/reshare — Share again: the owner's skill folder on
+     *  the server becomes the new version (409 ENOSOURCE when it has none). */
+    reshare: (id: number) =>
+      request<{ item: Artifact; changed: boolean }>(`/artifacts/${id}/reshare`, {
+        method: "POST",
+      }),
     /** `kept`: a shared one left your library but stays in the Hub. */
     remove: (id: number) =>
       request<{ ok: true; kept: boolean }>(`/artifacts/${id}`, { method: "DELETE" }),

client/src/pages/Artifacts.tsx

@@ -28,7 +28,9 @@
  * **Installed** instead of the Install button; **Uninstall** (a skill's
  * copies moved aside, a plugin `claude plugin uninstall`) is offered only in
  * the card's ⋯ menu. A skill follows its owner's folder (the server takes a
- * change there as a new snapshot when the Hub is listed); an installed copy
+ * change there as a new snapshot when the Hub is listed; **Share again**
+ * takes its folder on the server — or a plugin's copy — on a click, else
+ * asks for the folder and uploads it onto the same row); an installed copy
  * that differs from the newest version shows **Update** (a pack: "Update N"),
  * which replaces it after a confirmation, the old copy moved aside. Editing a skill
  * edits its SKILL.md (name, description, instructions — a new snapshot);
@@ -277,6 +279,53 @@ export function Artifacts() {
     }
   };
 
+  // Share again: the server's copy of the skill, else the folder picked again
+  // (uploaded onto the same row). Either way installers are offered Update.
+  const reshareInput = useRef<HTMLInputElement>(null);
+  const reshareRow = useRef<Artifact | null>(null);
+  useEffect(() => {
+    reshareInput.current?.setAttribute("webkitdirectory", "");
+  }, []);
+  const reshared = (changed: boolean) => {
+    toast.success(t(changed ? "reshareDone" : "reshareSame"));
+    load();
+  };
+  const reshare = async (a: Artifact) => {
+    try {
+      const r = await api.artifacts.reshare(a.id);
+      reshared(r.changed);
+    } catch (err) {
+      if ((err as { code?: string }).code !== "ENOSOURCE") return toast.error(err);
+      if (
+        !(await confirmDialog({
+          title: t("reshareAskTitle", { name: a.source ?? a.title }),
+          message: t("reshareAskBody", { name: a.source ?? a.title }),
+          confirmLabel: t("resharePick"),
+        }))
+      )
+        return;
+      reshareRow.current = a;
+      reshareInput.current?.click();
+    }
+  };
+  const reshareUpload = async (list: FileList | null) => {
+    const a = reshareRow.current;
+    reshareRow.current = null;
+    if (!a || !list?.length) return;
+    try {
+      const r = await api.artifacts.uploadSkills(
+        Array.from(list).map((file) => ({
+          file,
+          path: (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name,
+        })),
+        { id: String(a.id) }
+      );
+      reshared(r.items.some((i) => i.changed !== false));
+    } catch (err) {
+      toast.error(err);
+    }
+  };
+
   const [renaming, setRenaming] = useState<Artifact | null>(null);
 
   const remove = async (a: Artifact) => {
@@ -442,6 +491,7 @@ export function Artifacts() {
   const actionsFor = (a: Artifact): CardActions => ({
     onOpen: () => setDetailId(a.id),
     onShare: () => void share(a),
+    onReshare: () => void reshare(a),
     onRename: () => {
       setDetailId(null);
       setRenaming(a);
@@ -572,6 +622,17 @@ export function Artifacts() {
 
   return (
     <div className="animate-fade-in space-y-5" data-testid="artifacts-page">
+      <input
+        ref={reshareInput}
+        type="file"
+        multiple
+        hidden
+        data-testid="artifact-reshare-folder"
+        onChange={(e) => {
+          void reshareUpload(e.target.files);
+          e.target.value = "";
+        }}
+      />
       <div className="flex items-start justify-between gap-3">
         <div className="min-w-0">
           <h1 className="text-lg font-semibold text-fg-primary">{t("title")}</h1>
@@ -1066,6 +1127,8 @@ function EmptyState({
 type CardActions = {
   onOpen: () => void;
   onShare: () => void;
+  /** A skill of your own: its newest version, shared (installers get Update). */
+  onReshare: () => void;
   onRename: () => void;
   onDelete: () => void;
   onInstall: () => void;
@@ -1237,6 +1300,7 @@ function ArtifactMenu({
   menu,
   onOpen,
   onShare,
+  onReshare,
   onRename,
   onDelete,
   onInstall,
@@ -1297,6 +1361,9 @@ function ArtifactMenu({
               {t(hubOnly ? "hubRemove" : a.shared ? "unshare" : "share")}
             </MenuItem>
           )}
+          {server && a.kind === "skill" && (
+            <MenuItem onSelect={pick(onReshare)}>{t("reshare")}</MenuItem>
+          )}
           <MenuItem onSelect={pick(onRename)}>{t("rename")}</MenuItem>
           {!hubOnly && (
             <MenuItem danger onSelect={pick(onDelete)}>
@@ -1447,6 +1514,7 @@ function DetailDialog({
   canInstall,
   onClose,
   onShare,
+  onReshare,
   onRename,
   onDelete,
   onInstall,
@@ -1611,6 +1679,11 @@ function DetailDialog({
                 {t(hubOnly ? "hubRemove" : a.shared ? "unshare" : "share")}
               </button>
             )}
+            {server && a.kind === "skill" && (
+              <button type="button" className={secondary} onClick={onReshare}>
+                {t("reshare")}
+              </button>
+            )}
             <button type="button" className={secondary} onClick={onRename}>
               {t("rename")}
             </button>

client/src/pages/__tests__/Artifacts.test.tsx

@@ -46,6 +46,7 @@ vi.mock("../../lib/api", () => ({
       addPlugin: vi.fn(),
       inspectMarket: vi.fn(),
       uploadSkills: vi.fn(),
+      reshare: vi.fn(),
       writeSkill: vi.fn(),
       uploadFile: vi.fn(),
       candidates: vi.fn(),
@@ -394,6 +395,47 @@ describe("Artifacts", () => {
     expect(calls[calls.length - 1]?.[0].title).toMatch(/Remove “hub-only” from the Hub/);
   });
 
+  it("Share again takes the server's copy, else uploads the picked folder onto that skill", async () => {
+    vi.mocked(api.artifacts.uploadSkills).mockClear();
+    vi.mocked(api.artifacts.settings).mockResolvedValue({
+      serverMode: true,
+      canShare: true,
+      installsEnabled: true,
+      canManage: true,
+    });
+    vi.mocked(api.artifacts.list).mockResolvedValue({
+      items: [item({ id: 2, kind: "skill", title: "sg-flow", source: "sg-flow", shared: true })],
+    });
+    vi.mocked(api.artifacts.reshare).mockResolvedValueOnce({
+      item: item({ id: 2 }),
+      changed: true,
+    });
+    const user = userEvent.setup();
+    open();
+    const card = await screen.findByTestId("artifact-2");
+    await menuAction(user, "Share again", card);
+    await waitFor(() => expect(api.artifacts.reshare).toHaveBeenCalledWith(2));
+    expect(api.artifacts.uploadSkills).not.toHaveBeenCalled();
+
+    // No copy on the server: the folder is asked for and lands on THIS row.
+    vi.mocked(api.artifacts.reshare).mockRejectedValueOnce(
+      Object.assign(new Error("no copy"), { code: "ENOSOURCE" })
+    );
+    vi.mocked(confirmDialog).mockResolvedValueOnce(true);
+    vi.mocked(api.artifacts.uploadSkills).mockResolvedValueOnce({
+      items: [{ ...item({ id: 2 }), changed: true }],
+    });
+    await menuAction(user, "Share again", card);
+    await waitFor(() => expect(confirmDialog).toHaveBeenCalled());
+    const md = new File(["---\nname: sg-flow\n---\n"], "SKILL.md");
+    await user.upload(screen.getByTestId("artifact-reshare-folder"), md);
+    await waitFor(() =>
+      expect(api.artifacts.uploadSkills).toHaveBeenCalledWith([{ file: md, path: "SKILL.md" }], {
+        id: "2",
+      })
+    );
+  });
+
   it("offers Update for an installed skill its owner changed, after a confirmation", async () => {
     vi.mocked(api.artifacts.list).mockResolvedValue({
       items: [

client/src/pages/__tests__/__snapshots__/screens.snapshot.test.tsx.snap

@@ -7316,7 +7316,7 @@ exports[`screen snapshots > Settings — about 1`] = `
                 <span
                   class="text-status-warning/90"
                 >
-                  UI build v2.8.43 (rebuild client to match)
+                  UI build v2.8.45 (rebuild client to match)
                 </span>
               </p>
             </div>

docs/API.md

@@ -1063,7 +1063,7 @@ cannot collide on `index.lock`.
 | `push` | `git push -u <remote> HEAD` — the branch's upstream remote, else the only remote, else `origin`, else `400 ENOREMOTE` | — |
 | `stage` | `git add -- <paths>` | `{"paths": ["..."]}` |
 | `unstage` | `git restore --staged -- <paths>` (a staged rename also passes its original path, so both halves unstage) | `{"paths": ["..."]}` |
-| `discard` | `git restore --source=HEAD --staged --worktree` (tracked) / `git clean -fd` (untracked) | `{"paths": ["..."], "confirm": true}` |
+| `discard` | `git restore --source=HEAD --staged --worktree` (tracked) / `git clean -fd` (untracked); with `hunks` (a partly ticked file's ticked change blocks, named as in `commit`), `git apply -R` of only those blocks off the working tree first — every patch built before any is applied, so a stale one is `409 EHUNKGONE` with nothing undone | `{"paths": ["..."], "confirm": true}` / `{"paths": [], "hunks": {"<path>": [{"hunk": "@@ … @@", "blocks": [0]}]}, "context": 3, "confirm": true}` |
 | `stage-hunk` | `git apply --cached` of ONE hunk of `git diff -U<context> HEAD -- <path>` — or, with `block`, of only that hunk's `block`-th run of +/- lines (the other runs folded into context, as an edited `git add -p` hunk) | `{"path": "...", "hunk": "@@ -1,2 +1,3 @@", "block": 0, "context": 3}` |
 | `discard-hunk` | `git apply -R` of that one hunk (or that one `block` of it), off the working tree | `{"path": "...", "hunk": "@@ ... @@", "block": 0, "context": 3, "confirm": true}` |
 | `commit` | `git add -A` then `git commit -m <message>`, or the index as it stands with `only: "staged"`, or — with `paths` — `git commit --only -- <paths>`: exactly those files' working-tree content (an untracked one is added first, and taken back out if the commit fails), every other change left as it was | `{"message": "...", "only": "staged"}` / `{"message": "...", "paths": ["..."]}` |
@@ -3156,7 +3156,7 @@ POST   /api/artifacts/page                     {url, title?, description?}
 POST   /api/artifacts/file                     {laneId, path, title?, sessionId?}
 POST   /api/artifacts/file/upload              multipart: files (one), title?, description? → {item}
 POST   /api/artifacts/skill                    {name, laneId?, title?, description?}
-POST   /api/artifacts/skill/upload             multipart: files, paths (JSON, each file's relative path), name?, title?, description? → {items}
+POST   /api/artifacts/skill/upload             multipart: files, paths (JSON, each file's relative path), name?, title?, description?, id? → {items} — a skill named like one the caller already has becomes its new version (`replaced`, `changed`); `id` = Share again onto that row
 POST   /api/artifacts/skill/new                {name, description, content, title?} → {item, items}
 POST   /api/artifacts/plugin/inspect           {market} → {market, name, description, plugins: [{name, key, description, version, category}]}
 POST   /api/artifacts/plugin                   {key: "name@marketplace", market: "owner/repo" | git URL | marketplace.json URL, title?, description?}
@@ -3166,6 +3166,7 @@ DELETE /api/artifacts/:id                      {ok, kept} — kept: a shared row
 GET    /api/artifacts/:id/raw?path=&download=1 one snapshot file (sandbox CSP, nosniff)
 POST   /api/artifacts/:id/install              {replace?, update?} → {installed, replaced?}
 POST   /api/artifacts/:id/uninstall            → {uninstalled, paths}
+POST   /api/artifacts/:id/reshare              → {item, changed} — Share again (skill, owner): the owner's folder on this server becomes the new version and the row is shared; 409 ENOSOURCE when the server has no copy
 GET    /api/artifacts/:id/installs             {items: [{user, mine, at, replaced, paths?}], unrecorded}
 POST   /api/artifacts/:id/claim                → {item} — the suggested user, or an admin
 POST   /api/artifacts/:id/decline              → {id, declined} — the suggested user
@@ -3177,6 +3178,7 @@ What agents produced, per OWNER (`server/lib/artifacts.js`, plan: `docs/plans/ar
 - **page** — a claude.ai link (`https://claude.ai/…` only, `400 EBADURL`), one row per owner and link. A session's `Artifact` tool publish — or a Claude Docs `batch` that creates a doc (`container.create`; its title is the doc's name, later batches are skipped) — is captured from its PostToolUse hook (a doc's own `frame.artifactUrl`; for a publish the first `https://claude.ai/…artifact/…` in `tool_response`), owned by the session's workspace owner — or, for a session no workspace owns (a member's `claude` started from their own terminal under S3), by the member whose account sent the hook (by its connection's uid, never the body); the host account names nobody, so such a page from the host stays unowned, with `suggested_owner_id` set to the owner of the workspace whose folder holds the session's `cwd` (else, under S3, the member whose home it is).
 - **file** — `candidates` are the documents (html, md, pdf, images, csv, office…) the workspace's sessions wrote with Write/Edit/MultiEdit/NotebookEdit, inside its folder. **Captured at Stop:** when a session a workspace owns sends `Stop` or `SessionEnd`, each `.pptx`/`.docx`/`.xlsx`/`.pdf`/`.html` in the workspace it created or changed since it started (a repo's untracked or modified files — an HTML file only when untracked — or a plain folder's files; at most 20 per stop, ≤ 25 MB) is snapshotted into the workspace owner's library as `auto: true` (shown **Auto**), off the hook's response path. The same file at the mtime its snapshot recorded is skipped; a changed one replaces that row's snapshot; a file pinned by hand is left alone. A pin is read under the download route's guards (`lanePath`, `resolveInLane`, `ESECRET`, ≤ 25 MB, `413 ETOOBIG`) and SNAPSHOTTED to `<data dir>/artifacts/<random>/`.
 - **skill** — the caller's own `~/.claude/skills/<name>` (their member home under S3; the host's for an admin or in local mode, else `409 ENOACCOUNT`) or a workspace's `.claude/skills/<name>`. Snapshotted whole: ≤ 300 files, ≤ 5 MB, a symlink anywhere is `ESYMLINK`, a secret-looking file name (`.env`, `*.pem`, `id_rsa`, `.netrc`…, or a data file named `*token*`/`*secret*`/`*password*`/`*credential*` — the word alone does not count in Markdown, source code or images, e.g. `design-tokens.md`) `403 ESECRET`.
+- **Share again** (a skill's ⋯ menu and detail sheet, its owner, server mode) — `reshare` takes the owner's skill folder on THIS server as the new snapshot: the row's source folder, else the same-named `skills/<name>` of a plugin the owner installed at user scope (`installed_plugins.json`, the most recently updated one, never outside their `~/.claude/plugins/`), and shares the row; installers are then offered **Update**. With no copy on the server (a skill uploaded from a browser) it answers `409 ENOSOURCE` and the page asks for the skill's folder, uploaded with `id` onto that row. An upload whose skill is named like one the uploader already has (not a workspace's) also replaces that row's version rather than adding a twin.
 - **file upload** — one file from the user's computer (≤ 25 MB, `413 ETOOBIG`), snapshotted under its own base name (no folder kept).
 - **skill upload / new** — a skill made from files rather than picked: one Markdown/text file of any name becomes `SKILL.md`; several files or a picked/dropped folder (`paths` keeps the layout) need a `SKILL.md` (at the top or in one folder, which is stripped — `400 ENOSKILLMD` otherwise); a single `.zip`/`.skill` is unpacked (sizes checked from its directory first, a symlink entry `ESYMLINK`, `__MACOSX`/`.DS_Store`/`.git`/`node_modules` skipped); an upload holding several skill folders makes one artifact per skill, named by its folder, and stores NOTHING if any of them fails. The `name` the user typed (only for a single skill; else the frontmatter `name:`, the folder or the file name) is made a folder name (`skillSlug`: marks dropped, other characters → `-`; `400 EBADNAME` if nothing is left) and written into `SKILL.md`'s frontmatter as `name:`; a `description` given replaces the frontmatter's, and a skill with none anywhere is `400 ENODESCRIPTION`. Paths are relative with no `..` (`EBADPATH`); the same limits and `ESECRET` as a picked skill. `new` writes `SKILL.md` from `content` the same way.
 - **plugin** — only the spec and its marketplace source (`EBADPLUGIN`, `EBADMARKET`: `owner/repo`, a `validateRemoteUrl` URL, or an https link to a `marketplace.json`); no files. A GitHub web link becomes `owner/repo`, and a forge's `…/src/…`, `…/tree/…`, `…/blob/…` suffix or trailing slash is trimmed. The same `key` added again by its owner updates that row. **inspect** reads the marketplace's `.claude-plugin/marketplace.json` to list its plugins: a git link is cloned shallow, blob-less and without checkout into a temp dir that is removed after, with every credential helper switched off and no prompt (a repository that needs a login is `502 ENEEDLOGIN`; type the key by hand — installing then uses each user's own git login), https only (an ssh link is `400 ESSHMARKET`); a repo with only a `plugin.json` is `400 ENOTMARKET`; unreachable `502 EMARKETFETCH`. It reaches any https host a signed-in user names, like `publish` does — no login is ever sent with it.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "agenthub",
-  "version": "2.8.43",
+  "version": "2.8.45",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "agenthub",
-      "version": "2.8.43",
+      "version": "2.8.45",
       "hasInstallScript": true,
       "license": "UNLICENSED",
       "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "agenthub",
-  "version": "2.8.43",
+  "version": "2.8.45",
   "bin": {
     "agenthub": "bin/agenthub.js"
   },

server/__tests__/artifacts.test.js

@@ -665,6 +665,105 @@ describe("skills from files or written", () => {
     assert.equal(bad.body.error.code, "EBADNAME");
   });
 
+  it("updates the uploader's same-named skill instead of adding a twin", async () => {
+    const md = (v) => `---\nname: sg-again\ndescription: version ${v}\n---\nBody ${v}.\n`;
+    const first = await upload("/api/artifacts/skill/upload", [["sg-again/SKILL.md", md(1)]]);
+    assert.equal(first.status, 201, JSON.stringify(first.body));
+    const id = first.body.items[0].id;
+    const again = await upload("/api/artifacts/skill/upload", [["sg-again/SKILL.md", md(2)]]);
+    assert.equal(again.status, 201, JSON.stringify(again.body));
+    assert.equal(again.body.items[0].id, id);
+    assert.equal(again.body.items[0].replaced, true);
+    assert.equal(again.body.items[0].changed, true);
+    assert.equal(again.body.items[0].description, "version 2");
+    assert.match(snapText(again.body.items[0]), /Body 2\./);
+    const rows = db
+      .prepare("SELECT COUNT(*) AS n FROM artifacts WHERE kind = 'skill' AND source = 'sg-again'")
+      .get();
+    assert.equal(rows.n, 1);
+    const same = await upload("/api/artifacts/skill/upload", [["sg-again/SKILL.md", md(2)]]);
+    assert.equal(same.body.items[0].changed, false);
+  });
+
+  it("Share again: an uploaded skill asks for its folder, which replaces that row", async () => {
+    const md = (v) => `---\nname: sg-up\ndescription: d\n---\nUp ${v}.\n`;
+    const first = await upload("/api/artifacts/skill/upload", [["sg-up/SKILL.md", md(1)]]);
+    const id = first.body.items[0].id;
+    const no = await request("POST", `/api/artifacts/${id}/reshare`);
+    assert.equal(no.status, 409);
+    assert.equal(no.body.error.code, "ENOSOURCE");
+    // The folder picked again, under any folder name: onto THIS row.
+    const r = await upload("/api/artifacts/skill/upload", [["renamed/SKILL.md", md(2)]], {
+      id: String(id),
+    });
+    assert.equal(r.status, 201, JSON.stringify(r.body));
+    assert.equal(r.body.items[0].id, id);
+    assert.equal(r.body.items[0].source, "sg-up");
+    assert.match(snapText(r.body.items[0]), /^---\nname: sg-up\n[\s\S]*Up 2\./);
+    const two = await upload(
+      "/api/artifacts/skill/upload",
+      [
+        ["p/a/SKILL.md", "---\nname: a\ndescription: d\n---\n"],
+        ["p/b/SKILL.md", "---\nname: b\ndescription: d\n---\n"],
+      ],
+      { id: String(id) }
+    );
+    assert.equal(two.body.error.code, "EBADUPLOAD");
+  });
+
+  it("Share again takes the owner's folder, else the skill of an installed plugin", async () => {
+    const home = process.env.CLAUDE_HOME;
+    // An uploaded skill whose name a user-scope plugin also ships.
+    const first = await upload("/api/artifacts/skill/upload", [
+      ["sg-plug/SKILL.md", "---\nname: sg-plug\ndescription: d\n---\nOld.\n"],
+    ]);
+    const id = first.body.items[0].id;
+    const writePlugin = (ver, text) => {
+      const at = path.join(home, "plugins", "cache", "m", "p", ver);
+      fs.mkdirSync(path.join(at, "skills", "sg-plug"), { recursive: true });
+      fs.writeFileSync(path.join(at, "skills", "sg-plug", "SKILL.md"), text);
+      return at;
+    };
+    const v1 = writePlugin("1.0.0", "---\nname: sg-plug\ndescription: d\n---\nPlugin one.\n");
+    const v2 = writePlugin("2.0.0", "---\nname: sg-plug\ndescription: d\n---\nPlugin two.\n");
+    fs.writeFileSync(
+      path.join(home, "plugins", "installed_plugins.json"),
+      JSON.stringify({
+        version: 2,
+        plugins: {
+          "p@m": [{ scope: "user", installPath: v2, lastUpdated: "2026-10-30T00:00:00Z" }],
+          "old@m": [{ scope: "user", installPath: v1, lastUpdated: "2026-01-01T00:00:00Z" }],
+          "proj@m": [
+            { scope: "project", installPath: "/etc", lastUpdated: "2027-01-01T00:00:00Z" },
+          ],
+        },
+      })
+    );
+    const r = await request("POST", `/api/artifacts/${id}/reshare`);
+    assert.equal(r.status, 200, r.text);
+    assert.equal(r.body.changed, true);
+    assert.match(snapText(r.body.item), /Plugin two\./);
+    assert.equal((await request("POST", `/api/artifacts/${id}/reshare`)).body.changed, false);
+
+    // The owner's own ~/.claude/skills folder outranks a plugin's copy.
+    const own = path.join(home, "skills", "sg-plug");
+    fs.mkdirSync(own, { recursive: true });
+    fs.writeFileSync(
+      path.join(own, "SKILL.md"),
+      "---\nname: sg-plug\ndescription: d\n---\nMine.\n"
+    );
+    const mine = await request("POST", `/api/artifacts/${id}/reshare`);
+    assert.equal(mine.body.changed, true);
+    assert.match(snapText(mine.body.item), /Mine\./);
+    // Recorded as the folder's state: the 15 s sync does not take it twice.
+    assert.deepEqual(
+      artifacts.syncSkillSources({ force: true }).filter((c) => c.id === id),
+      []
+    );
+    fs.rmSync(path.join(home, "plugins"), { recursive: true, force: true });
+    fs.rmSync(own, { recursive: true, force: true });
+  });
+
   it("keeps an uploaded file as a snapshot, by its own base name", async () => {
     const r = await upload("/api/artifacts/file/upload", [["report.html", "<h1>x</h1>"]], {
       title: "Report",

server/__tests__/git-diff-ops.test.js

@@ -851,6 +851,51 @@ describe("runGitAction — one change block inside a hunk (issue #50)", () => {
     assert.equal(fs.readFileSync(path.join(LANE, "tail.txt"), "utf8"), "l1\nl2\nl3\nl4\nl5\nl6");
   });
 
+  it("discards only the ticked blocks and whole files, nothing unticked (issue #87)", async () => {
+    const edited = threeBlocks();
+    write(LANE, "keep.txt", "untouched by discard\n");
+    write(LANE, "drop.txt", "gone\n");
+    const [hunk] = await hunkOf();
+    await assert.rejects(
+      () =>
+        runGitAction(LANE, "discard", {
+          paths: ["drop.txt"],
+          hunks: { "near.txt": [{ hunk: hunk.header, blocks: [0, 2] }] },
+        }),
+      { code: "ECONFIRM" }
+    );
+    await runGitAction(LANE, "discard", {
+      paths: ["drop.txt"],
+      hunks: { "near.txt": [{ hunk: hunk.header, blocks: [0, 2] }] },
+      confirm: true,
+    });
+    const want = [...edited];
+    want.splice(11, 0, "line 11");
+    want.splice(3, 2, "line 4", "line 5");
+    assert.deepEqual(read(), [...want, ""]);
+    assert.equal(fs.existsSync(path.join(LANE, "drop.txt")), false);
+    assert.equal(fs.readFileSync(path.join(LANE, "keep.txt"), "utf8"), "untouched by discard\n");
+  });
+
+  it("discards ticked blocks alone, and refuses a stale one with nothing undone", async () => {
+    const edited = threeBlocks();
+    const [hunk] = await hunkOf();
+    await assert.rejects(
+      () =>
+        runGitAction(LANE, "discard", {
+          hunks: { "near.txt": [{ hunk: "@@ -1,2 +1,2 @@", blocks: [0] }] },
+          confirm: true,
+        }),
+      { code: "EHUNKGONE" }
+    );
+    assert.deepEqual(read(), [...edited, ""]);
+    await runGitAction(LANE, "discard", {
+      hunks: { "near.txt": [{ hunk: hunk.header, blocks: [1] }] },
+      confirm: true,
+    });
+    assert.deepEqual(read(), [...edited.filter((l) => l !== "INSERTED"), ""]);
+  });
+
   it("refuses a block the hunk does not have", async () => {
     threeBlocks();
     const [hunk] = await hunkOf();

server/lib/artifacts.js

@@ -1125,8 +1125,20 @@ function saveSkillFiles(req, { name, files, title, description }) {
  * `paths`). Answers every skill it made. Nothing is stored unless every
  * skill in the upload passes.
  */
-function uploadSkills(req, { uploads, name, title, description }) {
+function uploadSkills(req, { uploads, name, title, description, id }) {
+  // `id`: Share again for a skill the server has no copy of — the upload
+  // replaces THAT row (one skill, named as the row is).
+  let onto = null;
+  if (id != null && id !== "") {
+    onto = load(req, id);
+    if (!canChange(req, onto)) throw fail("EFORBIDDEN", "only its owner changes an artifact");
+    if (onto.kind !== "skill") throw fail("EBADKIND", "only a skill is shared again");
+    name = onto.source;
+  }
   const found = skillsFromUpload(uploads || [], { name, description });
+  if (onto && found.length !== 1) {
+    throw fail("EBADUPLOAD", "choose the folder or .zip of this one skill");
+  }
   const typed = typeof name === "string" && name.trim();
   const prepared = found.map((sk) => ({
     name: validSkillName(found.length === 1 && typed ? typed : sk.fallbackName || ""),
@@ -1140,16 +1152,46 @@ function uploadSkills(req, { uploads, name, title, description }) {
     withFrontmatter(md.data.toString("utf8"), p.name, found.length === 1 ? description : "");
     checkSkillFiles(p.files);
   }
-  return prepared.map((p) =>
-    saveSkillFiles(req, {
+  return prepared.map((p) => {
+    // A skill its uploader already has (same name, not a workspace's) gets
+    // the new version on that row — installers see Update — never a twin.
+    const own = onto || ownSkillRow(req, p.name);
+    if (own) return replaceUploaded(req, own, p, found.length === 1 ? description : "");
+    return saveSkillFiles(req, {
       name: p.name,
       files: p.files,
       title: found.length === 1 ? title : "",
       description: found.length === 1 ? description : "",
-    })
+    });
+  });
+}
+
+/** The caller's newest skill row of that name taken from no workspace, or null. */
+function ownSkillRow(req, name) {
+  const owner = req?.user ? req.user.id : null;
+  return (
+    sql(
+      `SELECT * FROM artifacts WHERE kind = 'skill' AND source = ? AND lane_id IS NULL
+         AND snapshot IS NOT NULL AND owner_id IS ? ORDER BY updated_at DESC, id DESC LIMIT 1`
+    ).get(name, owner) || null
   );
 }
 
+/** An uploaded skill onto an existing row: same frontmatter rules as a new one. */
+function replaceUploaded(req, row, { name, files }, description) {
+  const md = files.find((f) => f.path === "SKILL.md");
+  const text = md.data.toString("utf8");
+  if (text.includes("\uFFFD")) throw fail("EBADSKILL", "SKILL.md is not a UTF-8 text file");
+  const fixed = Buffer.from(withFrontmatter(text, name, description), "utf8");
+  const all = [{ path: "SKILL.md", data: fixed }, ...files.filter((f) => f !== md)];
+  checkSkillFiles(all);
+  const changed = contentHash(all) !== snapshotVersion(row);
+  // The owner's folder as it is now (like `storeSkill`): only a LATER change
+  // to it replaces this upload.
+  if (changed) replaceSnapshot(row, all, sourceHash(row) ?? row.source_hash);
+  return { ...shareNow(req, row.id, changed), replaced: true, changed };
+}
+
 /** A skill written in the dialog: a name, a description and its instructions. */
 function writeSkill(req, { name, description, content, title }) {
   const n = validSkillName(name);
@@ -1936,6 +1978,23 @@ function syncOne(row) {
   } catch {
     return false;
   }
+  try {
+    replaceSnapshot(row, files, st.hash);
+  } catch {
+    return false;
+  }
+  return true;
+}
+
+/**
+ * Point a skill row at a NEW snapshot holding `files` (`[{path, data}]`, already
+ * checked), then drop the old one — never a write into the snapshot being
+ * read. Installers then see Update (`updateCheck`). `sourceHash` is the
+ * source folder's state to record, so `syncOne` takes only a LATER change.
+ * The description follows SKILL.md's only while it still says what the old
+ * one did.
+ */
+function replaceSnapshot(row, files, sourceHash) {
   const snap = newSnapshotDir();
   let total = 0;
   const next = [];
@@ -1947,11 +2006,10 @@ function syncOne(row) {
       total += f.data.length;
       next.push({ path: f.path, size: f.data.length });
     }
-  } catch {
+  } catch (err) {
     dropSnapshot(snap.id);
-    return false;
+    throw err;
   }
-  // The description follows SKILL.md's only while it still says what the old one did.
   const md = (list) => list.find((f) => f.path === "SKILL.md");
   let oldSummary = "";
   try {
@@ -1970,9 +2028,96 @@ function syncOne(row) {
   sql(
     `UPDATE artifacts SET snapshot = ?, files = ?, size = ?, version = ?, source_hash = ?,
             description = ?, updated_at = strftime('%Y-%m-%dT%H:%M:%fZ','now') WHERE id = ?`
-  ).run(snap.id, JSON.stringify(next), total, st.hash, st.hash, description, row.id);
+  ).run(
+    snap.id,
+    JSON.stringify(next),
+    total,
+    contentHash(files),
+    sourceHash ?? null,
+    description,
+    row.id
+  );
   if (row.snapshot && SNAPSHOT_RE.test(row.snapshot)) dropSnapshot(row.snapshot);
-  return true;
+}
+
+/**
+ * The owner's skill folder on THIS server as it is now, for Share again:
+ * the row's own source folder (`sourceDirOf`), else — a skill not taken from
+ * a workspace — the same-named skill of a plugin the owner installed at user
+ * scope (`installed_plugins.json`; the most recently updated when several
+ * have it), never outside the owner's `~/.claude/plugins/`. Answers
+ * `{st, fromSource}` (`folderState`) or null when the server has no copy (an
+ * uploaded skill: its owner picks the folder again).
+ */
+function machineSkill(row) {
+  const src = sourceDirOf(row);
+  const st = src && folderState(src.dir, src.top);
+  if (st) return { st, fromSource: true };
+  if (!src || row.lane_id != null) return null;
+  const top = path.join(src.top, "plugins");
+  let installed = {};
+  try {
+    const user = sql("SELECT id, username, role FROM users WHERE id = ?").get(row.owner_id);
+    const file = path.join(top, "installed_plugins.json");
+    const text =
+      user && ownAccount({ user }).acct
+        ? require("./run-as").readFileSafe(file, "utf8", { max: 4 << 20 })
+        : fs.readFileSync(file, "utf8");
+    installed = JSON.parse(text)?.plugins || {};
+  } catch {
+    return null;
+  }
+  let best = null;
+  for (const entries of Object.values(installed)) {
+    for (const e of Array.isArray(entries) ? entries : []) {
+      if (!e || e.scope !== "user" || typeof e.installPath !== "string") continue;
+      const st2 = folderState(path.join(e.installPath, "skills", row.source), top);
+      const at = Date.parse(e.lastUpdated || e.installedAt || "") || 0;
+      if (st2 && (!best || at > best.at)) best = { st: st2, at };
+    }
+  }
+  return best ? { st: best.st, fromSource: false } : null;
+}
+
+/**
+ * Share again: take the owner's skill folder on this server as the row's new
+ * snapshot (`machineSkill`) and share it (server mode), so installers are
+ * offered Update. ENOSOURCE when the server has no copy — the client then
+ * asks for the folder or .zip and uploads it onto this row (`uploadSkills`
+ * with `id`). Answers `{item, changed}`.
+ */
+function reshareSkill(req, id) {
+  const row = load(req, id);
+  if (!canChange(req, row)) throw fail("EFORBIDDEN", "only its owner changes an artifact");
+  if (row.kind !== "skill") throw fail("EBADKIND", "only a skill is shared again");
+  const found = machineSkill(row);
+  if (!found) {
+    throw fail("ENOSOURCE", "this server has no copy of the skill: choose its folder or .zip");
+  }
+  const files = found.st.read();
+  checkSkillFiles(files);
+  const changed = found.st.hash !== snapshotVersion(row);
+  if (changed) {
+    replaceSnapshot(row, files, found.fromSource ? found.st.hash : row.source_hash);
+  } else if (found.fromSource) {
+    sql("UPDATE artifacts SET source_hash = ? WHERE id = ?").run(found.st.hash, row.id);
+  }
+  return { item: shareNow(req, row.id, changed), changed };
+}
+
+/** Share a row (server mode, when it is not yet) and answer its view; `audit` names a new version. */
+function shareNow(req, id, changed) {
+  const row = sql("SELECT * FROM artifacts WHERE id = ?").get(id);
+  if (isServer() && row.shared !== 1) {
+    sql(
+      `UPDATE artifacts SET shared = 1, shared_at = strftime('%Y-%m-%dT%H:%M:%fZ','now'),
+              updated_at = strftime('%Y-%m-%dT%H:%M:%fZ','now') WHERE id = ?`
+    ).run(id);
+    audit(req, row, "shared");
+  } else if (changed && row.shared === 1) {
+    audit(req, row, "updated");
+  }
+  return view(sql("SELECT * FROM artifacts WHERE id = ?").get(id), req);
 }
 
 const SYNC_EVERY_MS = 15 * 1000;
@@ -2215,6 +2360,7 @@ module.exports = {
   availableSkills,
   addSkill,
   uploadSkills,
+  reshareSkill,
   writeSkill,
   uploadFile,
   skillSlug,

server/lib/git-diff.js

@@ -1241,16 +1241,18 @@ async function diffHunks(dir, file, context) {
  * in file order, to be applied FORWARD onto an index holding HEAD. Every
  * header is matched against a fresh diff like `hunkPatch`'s; null when one is
  * gone or names a block the hunk lacks. Each hunk's new-side start is left as
- * git wrote it — `git apply` locates a hunk by its old side.
+ * git wrote it — `git apply` locates a hunk by its old side. `reverse` cuts
+ * it for `apply -R` off the working tree instead (the partial discard, #87),
+ * where the NEW side is the one checked and every start stays git's own.
  */
-async function selectionPatch(dir, file, context, picks) {
+async function selectionPatch(dir, file, context, picks, reverse = false) {
   const diff = await diffHunks(dir, file, context);
   if (!diff || !picks.length) return null;
   const at = (header) => diff.hunks.findIndex((h) => h.slice(0, h.indexOf("\n")) === header);
   if (picks.some((p) => at(p.hunk) < 0)) return null;
   const bodies = [];
   for (const p of [...picks].sort((x, y) => at(x.hunk) - at(y.hunk))) {
-    const body = onlyBlock(diff.hunks[at(p.hunk)], p.blocks, false);
+    const body = onlyBlock(diff.hunks[at(p.hunk)], p.blocks, reverse);
     if (!body) return null;
     bodies.push(body);
   }

server/lib/git-ops.js

@@ -424,6 +424,13 @@ async function runGitAction(dir, action, body = {}) {
 
   if (action === "discard") {
     if (body.confirm !== true) throw bad("ECONFIRM", "discard requires confirm: true");
+    // Ticked change blocks of partly ticked files (#87) go first: each patch
+    // is built before any is applied, so a stale one refuses before the
+    // irreversible whole-file part below has run.
+    const partial = hasHunks(body) ? await discardSelection(dir, body) : null;
+    if (partial && !(Array.isArray(body.paths) && body.paths.length)) {
+      return done(action, partial);
+    }
     const paths = await resolvePaths(dir, body);
     const untracked = paths.filter((p) => p.code === "??").map((p) => p.path);
     // A rename's ORIGINAL path rides along: restoring only the new one would
@@ -431,7 +438,7 @@ async function runGitAction(dir, action, body = {}) {
     const tracked = paths
       .filter((p) => p.code !== "??")
       .flatMap((p) => (p.from && p.code.includes("R") ? [p.path, p.from] : [p.path]));
-    const out = [];
+    const out = partial ? [partial] : [];
     // Untracked files are deleted (git has no copy to restore); tracked ones
     // go back to HEAD in both gutters, so a staged-then-edited file lands in
     // one state rather than half-reverted.
@@ -825,18 +832,11 @@ function hasHunks(body) {
 const MAX_PARTIAL_FILES = 300;
 
 /**
- * JetBrains' partial commit: whole files (`paths`) plus, per file in `hunks`,
- * only the ticked change blocks — `{"<path>": [{hunk: "@@ … @@", blocks: [0]}]}`,
- * the hunks named as `stage-hunk` names them, at `context`. Built in a
- * TEMPORARY index (HEAD + the whole files + one patch per partial file from
- * `selectionPatch`, git's own fresh text, never the request's) and committed
- * from it, so the real index and the working tree are never in the way; after
- * the commit the real index entries of exactly those paths are reset to the
- * new HEAD, the rest of each partial file left as an unstaged change. Same
- * path rules as `commitPaths`; a partial file must be tracked (EUNTRACKED)
- * and not a rename, and a hunk the tree no longer has is EHUNKGONE.
+ * `body.hunks` checked for shape, and its files resolved as changed paths
+ * that may be taken in part: tracked (EUNTRACKED), not a rename, not in
+ * conflict, and not also named whole in `body.paths`.
  */
-async function commitSelection(dir, args, body) {
+async function partialPicks(dir, body, verb) {
   const picks = Object.entries(body.hunks);
   if (picks.length > MAX_PARTIAL_FILES) throw bad("EBADPATH", "too many files");
   for (const [, list] of picks) {
@@ -858,12 +858,54 @@ async function commitSelection(dir, args, body) {
   const conflicted = [...whole, ...part].find((p) => CONFLICT_CODES.has(p.code));
   if (conflicted) throw bad("ECONFLICTS", `${conflicted.path} is in conflict: resolve it first`);
   for (const p of part) {
-    if (p.code === "??") throw bad("EUNTRACKED", `${p.path} is untracked: commit it whole`);
-    if (p.code.includes("R")) throw bad("EBADPATH", `${p.path} is a rename: commit it whole`);
+    if (p.code === "??") throw bad("EUNTRACKED", `${p.path} is untracked: ${verb} it whole`);
+    if (p.code.includes("R")) throw bad("EBADPATH", `${p.path} is a rename: ${verb} it whole`);
     if (whole.some((w) => w.path === p.path)) {
       throw bad("EBADPATH", `${p.path} is named both whole and in part`);
     }
   }
+  return { picks, whole, part };
+}
+
+/**
+ * The partial discard (#87): per file in `hunks`, only the ticked change
+ * blocks are undone off the working tree — `selectionPatch` in reverse, git's
+ * own fresh text, never the request's — exactly what one `discard-hunk` per
+ * block would do, in one step. Every patch is built before the first is
+ * applied, so a stale selection refuses (EHUNKGONE) with nothing undone.
+ */
+async function discardSelection(dir, body) {
+  const { picks } = await partialPicks(dir, body, "discard");
+  const patches = [];
+  for (const [p, list] of picks) {
+    const patch = await selectionPatch(dir, p, body.context, list, true);
+    if (!patch)
+      throw bad("EHUNKGONE", `${p}: that change is no longer in the diff; refresh and retry`);
+    patches.push(patch);
+  }
+  // The patch names paths from the repo root, so it is applied there.
+  const top = (await git(dir, ["rev-parse", "--show-toplevel"])).stdout.trim();
+  const zero = Number(body.context) === 0 ? ["--unidiff-zero"] : [];
+  const out = [];
+  for (const patch of patches)
+    out.push(await git(top, ["apply", "-R", ...zero, "-"], { input: patch }));
+  return mergeResults(out);
+}
+
+/**
+ * JetBrains' partial commit: whole files (`paths`) plus, per file in `hunks`,
+ * only the ticked change blocks — `{"<path>": [{hunk: "@@ … @@", blocks: [0]}]}`,
+ * the hunks named as `stage-hunk` names them, at `context`. Built in a
+ * TEMPORARY index (HEAD + the whole files + one patch per partial file from
+ * `selectionPatch`, git's own fresh text, never the request's) and committed
+ * from it, so the real index and the working tree are never in the way; after
+ * the commit the real index entries of exactly those paths are reset to the
+ * new HEAD, the rest of each partial file left as an unstaged change. Same
+ * path rules as `commitPaths`; a partial file must be tracked (EUNTRACKED)
+ * and not a rename, and a hunk the tree no longer has is EHUNKGONE.
+ */
+async function commitSelection(dir, args, body) {
+  const { picks, whole, part } = await partialPicks(dir, body, "commit");
   const wholePaths = whole.flatMap((p) =>
     p.from && p.code.includes("R") ? [p.path, p.from] : [p.path]
   );

server/openapi-extra/artifacts.js

@@ -238,7 +238,7 @@ const paths = {
       summary: "Skills from files: a file, a folder, a .zip/.skill or several skills",
       operationId: "uploadArtifactSkills",
       description:
-        "`paths` is a JSON array of each file's relative path. Zip sizes are read before inflating; nothing is stored if any skill fails.",
+        "`paths` is a JSON array of each file's relative path. Zip sizes are read before inflating; nothing is stored if any skill fails. A skill whose name matches one the caller already has (not a workspace's) becomes that row's new version (`replaced: true`, `changed`) instead of a second row; `id` (Share again) puts the ONE uploaded skill onto that row, under the row's name.",
       requestBody: multipart(
         {
           files: { type: "array", items: { type: "string", format: "binary" } },
@@ -246,6 +246,7 @@ const paths = {
           name: { type: "string" },
           title: { type: "string" },
           description: { type: "string" },
+          id: { type: "string", description: "Share again: the skill row the upload replaces." },
         },
         ["files"]
       ),

server/openapi-extra/ops-more.js

@@ -1113,6 +1113,26 @@ const paths = {
       },
     },
   },
+  "/api/artifacts/{id}/reshare": {
+    post: {
+      tags: ["Artifacts"],
+      summary: "Share again: a skill's newest version from its owner's folder on this server",
+      operationId: "reshareArtifact",
+      description:
+        "The owner's skill folder (the row's source folder, else the same-named skill of a plugin the owner installed at user scope) becomes the new snapshot, and the row is shared (server mode); installers are then offered Update. 409 ENOSOURCE when the server has no copy: upload the folder with `id` on /api/artifacts/skill/upload. Same-origin only.",
+      parameters: [pathParam("id", "Artifact id.")],
+      responses: {
+        200: ok("Taken.", {
+          item: { type: "object" },
+          changed: { type: "boolean" },
+        }),
+        400: errs("EBADKIND."),
+        403: errs("EFORBIDDEN."),
+        404: errs("ENOTFOUND."),
+        409: errs("ENOSOURCE."),
+      },
+    },
+  },
   "/api/artifacts/{id}/claim": {
     post: {
       tags: ["Artifacts"],

server/routes/artifacts.js

@@ -39,6 +39,7 @@ const STATUS = {
   ENEEDLOGIN: 502,
   ETOOBIG: 413,
   EOWNED: 409,
+  ENOSOURCE: 409,
 };
 
 function sendError(res, err) {
@@ -229,6 +230,7 @@ router.post(
       name: b.name,
       title: b.title,
       description: b.description,
+      id: b.id,
     });
     for (const item of items) changed(item);
     res.status(201).json({ items });
@@ -284,6 +286,19 @@ router.patch(
   })
 );
 
+// Share again: the owner's skill folder on this server becomes the new
+// version (installers see Update); 409 ENOSOURCE when the server has none —
+// the client then uploads the folder onto this row (`/skill/upload` + `id`).
+router.post(
+  "/:id/reshare",
+  sameOriginGuard,
+  wrap((req, res) => {
+    const out = artifacts.reshareSkill(req, req.params.id);
+    changed(out.item);
+    res.json(out);
+  })
+);
+
 router.delete(
   "/:id",
   sameOriginGuard,