Avoid using just a filename like "Update qtest.c"

Each git commit message subject should be sufficiently descriptive, and
the commit hook will alert students who fail to provide meaningful and
detailed subjects.

Change-Id: Iaddd15b1020bee3e3ea518145a99f617ca438ccd

Author: jserv

scripts/commit-msg.hook

@@ -283,6 +283,15 @@ validate_commit_message() {
   word_count=$(echo "$COMMIT_SUBJECT_TO_PROCESS" | wc -w)
   test "$word_count" -gt 1
   test $? -eq 0 || add_warning 1 "Commit subject should contain more than one word (e.g. 'Update dependencies' instead of 'Update')"
+
+  # 11. Avoid commit subject that simply states a file update (e.g. "Update console.c")
+  if [[ $COMMIT_SUBJECT_TO_PROCESS =~ ^Update[[:space:]]+([^[:space:]]+)$ ]]; then
+    candidate="${BASH_REMATCH[1]}"
+    # Only warn if the candidate filename ends with .c or .h
+    if [[ $candidate =~ \.(c|h)$ ]]; then
+      add_warning 1 "Avoid using just a filename like '$candidate'. Provide a functional, meaningful description"
+    fi
+  fi
 }
 
 unset GREP_OPTIONS