Adds an automatic compare link to the weekly release notes.

.github/workflows/weekly-build-notes.md

@@ -1,6 +1,7 @@
 > [!IMPORTANT]
 > Bleeding edge FreeCAD development builds for testing bugfixes, regressions, and recently implemented features. Do not use in a production environment.
 
+**Changes since last weekly:** <!--DIFF_LINK-->
 
 ### How-to use
 
@@ -8,7 +9,7 @@
 2. Unpack the bundle to any folder on your system
 3. Launch the application
     - **Windows**
-    Run `\bin\FreeCAD.exe` in the extracted directory
+    Run `\FreeCAD.exe` in the extracted directory
     - **macOS**
     Launch `/FreeCAD.app` in the extracted directory
     - **Linux**

.github/workflows/weekly-compare-link.yml

@@ -0,0 +1,140 @@
+name: Weekly compare link to release notes
+
+on:
+  release:
+    types: [published]   # run automatically when a (pre-)release is published
+  workflow_dispatch:      # allow manual runs too
+    inputs:
+      current_tag:
+        description: "Weekly tag (e.g., weekly-2026.01.07). Leave empty to auto-detect latest weekly pre-release."
+        required: false
+      dry_run:
+        description: "Only compute; do not update the release body."
+        required: false
+        type: boolean
+        default: false
+
+permissions:
+  contents: write        # required to PATCH the release body
+
+jobs:
+  update-notes:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Inject compare link into weekly release notes
+        uses: actions/github-script@v7
+        env:
+          # Pass manual inputs via env for convenience
+          CURRENT_TAG: ${{ github.event.inputs.current_tag }}
+          DRY_RUN: ${{ github.event.inputs.dry_run }}
+          PLACEHOLDER: "<!--DIFF_LINK-->"
+        with:
+          script: |
+            // Updates the current weekly release notes with a compare link to the previous weekly.
+            // Works for both release-published events and manual (workflow_dispatch) runs.
+            const owner = context.repo.owner;
+            const repo  = context.repo.repo;
+
+            const rx = /^weekly-(\d{4})\.(\d{2})\.(\d{2})$/;
+
+            // Determine currentTag:
+            // 1) Manual input via workflow_dispatch (env.CURRENT_TAG)
+            // 2) Tag from release event payload
+            // 3) Fallback: newest weekly pre-release
+            let currentTag = process.env.CURRENT_TAG || (context.payload?.release?.tag_name) || null;
+
+            async function detectLatestWeeklyTag() {
+              const releases = await github.paginate(github.rest.repos.listReleases, { owner, repo, per_page: 100 });
+              const cand = releases.find(r => r.prerelease && typeof r.tag_name === 'string' && rx.test(r.tag_name));
+              return cand?.tag_name || null;
+            }
+
+            if (!currentTag) {
+              currentTag = await detectLatestWeeklyTag();
+            }
+
+            if (!currentTag || !rx.test(currentTag)) {
+              core.info(`No weekly tag detected or tag format mismatch ('${currentTag}'). Skipping.`);
+              return;
+            }
+
+            // Resolve the current release object
+            let curRel;
+            try {
+              const { data } = await github.rest.repos.getReleaseByTag({ owner, repo, tag: currentTag });
+              curRel = data;
+            } catch (e) {
+              core.setFailed(`No release for tag ${currentTag}: ${e.message}`);
+              return;
+            }
+
+            // If event is a normal release (not pre-release), skip automatically-run case;
+            // but allow manual override (manual runs can patch any weekly tag).
+            const isManual = context.eventName === 'workflow_dispatch';
+            if (!isManual && !curRel.prerelease) {
+              core.info('Current release is not a pre-release; skipping (auto run).');
+              return;
+            }
+
+            // Helpers
+            const toPrevWeeklyTag = (tag) => {
+              const [, y, m, d] = tag.match(rx);
+              const dt = new Date(Date.UTC(+y, +m - 1, +d));
+              const prev = new Date(dt.getTime() - 7 * 24 * 3600 * 1000); // minus 7 days
+              const iso = prev.toISOString().slice(0, 10); // YYYY-MM-DD
+              return `weekly-${iso.replace(/-/g, '.')}`;   // weekly-YYYY.MM.DD
+            };
+            const ymdKey = (t) => t.replace(rx, '$1$2$3'); // YYYYMMDD
+
+            async function tagExists(tag) {
+              try {
+                await github.rest.git.getRef({ owner, repo, ref: `tags/${tag}` });
+                return true;
+              } catch {
+                return false;
+              }
+            }
+
+            // Compute previous weekly deterministically, then fall back if needed
+            let prevTag = toPrevWeeklyTag(currentTag);
+            if (!(await tagExists(prevTag))) {
+              core.info(`Computed previous tag ${prevTag} not found; scanning older weeklies...`);
+              const releases = await github.paginate(github.rest.repos.listReleases, { owner, repo, per_page: 100 });
+              const curKey = ymdKey(currentTag);
+              const older = releases
+                .filter(r => r.prerelease && typeof r.tag_name === 'string' && rx.test(r.tag_name))
+                .map(r => ({ tag: r.tag_name, key: ymdKey(r.tag_name) }))
+                .filter(x => x.key < curKey)
+                .sort((a, b) => b.key.localeCompare(a.key)); // newest older first
+              if (!older.length) {
+                core.info('No older weekly found; nothing to do.');
+                return;
+              }
+              prevTag = older[0].tag;
+            }
+
+            const compareUrl = `https://github.com/${owner}/${repo}/compare/${prevTag}...${currentTag}`;
+            const head = `**Changes since last weekly (${prevTag} → ${currentTag}):**\n${compareUrl}\n`;
+
+            if (process.env.DRY_RUN === 'true') {
+              core.info(`[DRY RUN] Would update release ${currentTag} with: ${compareUrl}`);
+              return;
+            }
+
+            // Idempotent body update
+            let body = curRel.body || '';
+            if (body.includes(compareUrl)) {
+              core.info('Compare URL already present; done.');
+              return;
+            }
+            const placeholder = process.env.PLACEHOLDER || '<!--DIFF_LINK-->';
+            if (body.includes(placeholder)) {
+              body = body.replace(placeholder, compareUrl);
+            } else if (/\*\*Changes since last weekly:/i.test(body)) {
+              body = body.replace(/\*\*Changes since last weekly:[^\n]*\n?/i, head + '\n');
+            } else {
+              body += (body.endsWith('\n') ? '\n' : '\n\n') + head;
+            }
+
+            await github.rest.repos.updateRelease({ owner, repo, release_id: curRel.id, body });
+            core.info(`Release notes updated with compare link: ${compareUrl}`);