ci (check-whitespace): add links to job output

A message in the step log will refer to the Summary output.

The job summary output is using markdown to improve readability.  The
git commands and commits with errors are now in ordered lists.
Commits and files in error are links to the user's repository.

Signed-off-by: Chris. Webster <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: webstech

.github/workflows/check-whitespace.yml

@@ -20,46 +20,62 @@ jobs:
     - name: git log --check
       id: check_out
       run: |
+        baseSha=${{github.event.pull_request.base.sha}}
         problems=()
         commit=
         commitText=
-        lastcommit=
+        commitTextmd=
+        goodparent=
         while read dash sha etc
         do
           case "${dash}" in
           "---")
             if test -z "${commit}"
             then
-              lastcommit=${sha}
+              goodparent=${sha}
             fi
             commit="${sha}"
             commitText="${sha} ${etc}"
+            commitTextmd="[${sha}](https://github.com/${{ github.repository }}/commit/${sha}) ${etc}"
             ;;
           "")
             ;;
           *)
             if test -n "${commit}"
             then
-              problems+=("" "--- ${commitText}")
+              problems+=("1) --- ${commitTextmd}")
               echo ""
               echo "--- ${commitText}"
               commit=
             fi
-            problems+=("${dash} ${sha} ${etc}")
-            echo "${problems[-1]}"
+            case "${dash}" in
+            *:[1-9]*:) # contains file and line number information
+              dashend=${dash#*:}
+              problems+=("[${dash}](https://github.com/${{ github.repository }}/blob/${{github.event.pull_request.head.ref}}/${dash%%:*}#L${dashend%:}) ${sha} ${etc}")
+              ;;
+            *)
+              problems+=("\`${dash} ${sha} ${etc}\`")
+              ;;
+            esac
+            echo "${dash} ${sha} ${etc}"
             ;;
           esac
-        done <<< $(git log --check --pretty=format:"---% h% s" ${{github.event.pull_request.base.sha}}..)
+        done <<< $(git log --check --pretty=format:"---% h% s" ${baseSha}..)
 
         if test ${#problems[*]} -gt 0
         then
           if test -z "${commit}"
           then
-            lastcommit=${{github.event.pull_request.base.sha}}
+            goodparent=${baseSha: 0:7}
           fi
-          echo "A whitespace issue was found in one or more of the commits." >$GITHUB_STEP_SUMMARY
+          echo "🛑 Please review the Summary output for further information."
+          echo "### :x: A whitespace issue was found in one or more of the commits." >$GITHUB_STEP_SUMMARY
           echo "" >>$GITHUB_STEP_SUMMARY
-          echo "Run \`git rebase --whitespace=fix ${lastcommit}\` and \`git push --force\` to correct the problem." >>$GITHUB_STEP_SUMMARY
+          echo "Run these commands to correct the problem:" >>$GITHUB_STEP_SUMMARY
+          echo "1. \`git rebase --whitespace=fix ${goodparent}\`" >>$GITHUB_STEP_SUMMARY
+          echo "1. \`git push --force\`" >>$GITHUB_STEP_SUMMARY
+          echo " " >>$GITHUB_STEP_SUMMARY
+          echo "Errors:" >>$GITHUB_STEP_SUMMARY
           for i in "${problems[@]}"
           do
             echo "${i}" >>$GITHUB_STEP_SUMMARY