Update sync-main.yml

Author: dilanbhalla

.github/workflows/sync-main.yml

@@ -72,13 +72,17 @@ jobs:
           if [ -n "$pr_number" ]; then
             echo "PR from auto/sync-main-pr to main already exists (PR #$pr_number). Exiting gracefully."
           else
-            echo "PR does not exist. Creating one..."
-            gh pr create --repo microsoft/codeql --fill -B main -H auto/sync-main-pr \
-              --label 'autogenerated' \
-              --title 'Sync Main (autogenerated)' \
-              --body "This PR syncs the latest changes from \`codeql-cli/latest\` into \`main\`." \
-              --reviewer 'MathiasVP'
-              --reviewer 'ropwareJB'
+            if git fetch origin main auto/sync-main-pr && [ -n "$(git rev-list origin/main..origin/auto/sync-main-pr)" ]; then
+              echo "PR does not exist. Creating one..."
+              gh pr create --repo microsoft/codeql --fill -B main -H auto/sync-main-pr \
+                --label 'autogenerated' \
+                --title 'Sync Main (autogenerated)' \
+                --body "This PR syncs the latest changes from \`codeql-cli/latest\` into \`main\`." \
+                --reviewer 'MathiasVP'
+                --reviewer 'ropwareJB'
+            else
+              echo "No changes to sync from auto/sync-main-pr to main. Exiting gracefully."
+            fi
           fi
         env:
           GH_TOKEN: ${{ secrets.WORKFLOW_TOKEN }}