add pr comments for packages

.github/workflows/osgeo4w.yml

@@ -104,15 +104,56 @@ jobs:
 
           %GITHUB_WORKSPACE%\scripts\ccache -sv
 
-      - uses: actions/upload-artifact@v4
+      - id: upload
+        uses: actions/upload-artifact@v4
         with:
           name: ${{ matrix.pkg }}
           path: x86_64/
           retention-days: 1
 
       - name: Save build cache for push only
         uses: actions/cache/save@v4
-        if: ${{ github.event_name == 'push' }}
+        if: github.event_name == 'push'
         with:
           path: ccache
           key: build-ccache-osgeo4w-${{ matrix.pkg }}-${{ github.ref_name }}-${{ github.run_id }}
+
+      - run: npm install xml-js
+        if: github.event_name == 'pull_request'
+      - name: 'Post artifact download link and test results as comment on PR'
+        uses: actions/github-script@v7
+        if: github.event_name == 'pull_request'
+        with:
+          script: |
+            let fs = require('fs');
+            let tag = String(fs.readFileSync("src/${{ matrix.pkg }}/osgeo4w/build/Testing/TAG")).split("\r\n")[0]
+            let buildid = require('xml-js').xml2js(fs.readFileSync("src/${{ matrix.pkg }}/osgeo4w/build/Testing/" + tag + "/Done.xml"), {compact:true, ignoreDeclaration:true})['Done']['buildId']['_text']
+
+            const prComments = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number
+            });
+            const PREFIX = "## OSGeo4W package ${{ matrix.pkg }} ready!";
+            let body = PREFIX + "\n\n" + "Package of this PR is available for testing [here](${{ steps.upload.output.artifact-url }}).";
+            body += "\n\n*(Built from commit " + context.sha + ")*\n";
+            body += "\n\n*(Test results are [here](https://cdash.orfeo-toolbox.org/build/" + buildId + "))*";
+
+            const winBuildComment = prComments.data?.find(c => c.body.startsWith(PREFIX));
+            if (!!winBuildComment) {
+              // update the existing comment
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: winBuildComment.id,
+                body: body
+              });
+            } else {
+              // submit a new comment
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body: body
+              });
+            }