fix: escape rewrite replacement, diagnostic no-op commit, doc + askpass hardening

- Use function replacer in rewriteBody to prevent $& / $$ / $` / $' pattern
  corruption when alt text or siteUrl contains dollar-sign sequences
- Detect empty staged index after `git add -A` and throw a clear
  "No changes to publish" error instead of a cryptic git failure
- Correct README flat-slug description: single image → <slug>.<ext>,
  multiple → <slug>-1.<ext>, <slug>-2.<ext> (original filename discarded)
- Harden askpass dir resolution: show a Notice and return early if
  getFullPath is absent (desktop-only guard), rather than passing a bad path

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -36,7 +36,7 @@ An Obsidian plugin that publishes the active note as a Jekyll blog post via git.
 
 ## Image strategies
 
-**flat-slug** — all images for the post are copied flat into `<images-dir>/` and renamed to `<slug>-<original-name>`. Keeps the images directory shallow; suitable for sites with few images per post.
+**flat-slug** — all images for the post are copied flat into `<images-dir>/`. A single image is renamed to `<slug>.<ext>`; multiple images are renamed to `<slug>-1.<ext>`, `<slug>-2.<ext>`, … (the original Obsidian filename is discarded). Keeps the images directory shallow; suitable for sites with few images per post.
 
 **per-post-folder** — images are copied into `<images-dir>/<slug>/` preserving their original filenames. Keeps each post's images grouped together; suitable for posts with many images.
 

src/git.test.ts

@@ -50,3 +50,22 @@ test("second sync resets cleanly (fetch+reset path)", async () => {
   execFileSync("git", ["clone", bare, verify]);
   expect(readFileSync(join(verify, "_posts/second.md"), "utf8")).toBe("x");
 });
+
+test("commitAndPush rejects with diagnostic error when nothing is staged", async () => {
+  // Use a fresh base dir so we get a clean clone
+  const base2 = join(root, "work2");
+  mkdirSync(base2, { recursive: true });
+  const client = new ChildProcessGitClient({ baseDir: base2 });
+  // Clone and write a file, then commit it
+  await client.syncClone({ url: bare, branch: "main" });
+  await client.writeFiles([{ repoPath: "_posts/no-change.md", data: "same content" }]);
+  await client.commitAndPush({ message: "initial no-change", branch: "main", authorName: "t", authorEmail: "t@t" });
+
+  // Now sync again — tree now matches origin, re-writing the same content stages nothing
+  const client2 = new ChildProcessGitClient({ baseDir: base2 });
+  await client2.syncClone({ url: bare, branch: "main" });
+  await client2.writeFiles([{ repoPath: "_posts/no-change.md", data: "same content" }]);
+  await expect(
+    client2.commitAndPush({ message: "noop", branch: "main", authorName: "t", authorEmail: "t@t" })
+  ).rejects.toThrow(/no changes to publish/i);
+});

src/git.ts

@@ -66,6 +66,16 @@ export class ChildProcessGitClient implements GitClient {
 
   async commitAndPush(o: { message: string; branch: string; authorName?: string; authorEmail?: string }): Promise<void> {
     await this.git(this.workdir, ["add", "-A"]);
+    let hasChanges = false;
+    try {
+      await this.git(this.workdir, ["diff", "--cached", "--quiet"]);
+      // exit 0 => no staged changes
+    } catch {
+      hasChanges = true; // exit 1 => staged changes exist
+    }
+    if (!hasChanges) {
+      throw new Error("No changes to publish: the post and images are identical to what is already committed.");
+    }
     const cfg: string[] = [];
     if (o.authorName) cfg.push("-c", `user.name=${o.authorName}`);
     if (o.authorEmail) cfg.push("-c", `user.email=${o.authorEmail}`);

src/images.test.ts

@@ -67,4 +67,12 @@ describe("rewriteBody", () => {
       "![](/assets/img/post-1.png)\n![cap](/assets/img/post-2.jpeg)\n![d](/assets/img/post-3.svg)"
     );
   });
+
+  test("alt text containing $ patterns is preserved verbatim (no replacement-pattern corruption)", () => {
+    const slug = "my-post";
+    const body = "![a $& b $$ c](local.png)";
+    const refs = findImageRefs(body);
+    const { rewrittenBody } = planImages(refs, { slug, strategy: "flat-slug", imagesDir: "assets/img", body });
+    expect(rewrittenBody).toBe("![a $& b $$ c](/assets/img/my-post.png)");
+  });
 });

src/images.ts

@@ -69,7 +69,7 @@ export function rewriteBody(body: string, refs: ImageRef[], plan: ImagePlanItem[
   for (const ref of refs) {
     const siteUrl = url.get(ref.linktext);
     if (!siteUrl) continue;
-    out = out.replace(ref.raw, `![${ref.alt}](${siteUrl})`);
+    out = out.replace(ref.raw, () => `![${ref.alt}](${siteUrl})`);
   }
   return out;
 }

src/main.ts

@@ -44,10 +44,13 @@ export default class JekyllPublishPlugin extends Plugin {
       return;
     }
     const dir = normalizePath(this.app.vault.configDir + "/plugins/jekyll-publish");
+    const adapter = this.app.vault.adapter as any;
+    if (typeof adapter.getFullPath !== "function") {
+      new Notice("Jekyll Publish requires desktop Obsidian (filesystem access unavailable).");
+      return;
+    }
     const bridge = new AskpassBridge({
-      dir: (this.app.vault.adapter as any).getFullPath
-        ? (this.app.vault.adapter as any).getFullPath(dir)
-        : dir,
+      dir: adapter.getFullPath(dir),
       onPrompt: (prompt) => this.promptCredential(prompt),
     });
     try {