Skip commit hashes for spell check

The commit 4b1025c enforces American English in commit messages, but the
spell checker might get confused with git commit hashes. Now, the hook
looks for the word commit followed by a space and a Git hash of 7-40 hex
characters. It replaces this entire pattern with the word commit.

Change-Id: Ie718004a70dd27c0a64ac8af531395bd3d6fd6e1

Author: jserv

scripts/commit-msg.hook

@@ -344,8 +344,11 @@ validate_commit_message() {
     add_warning 1 "Commit message appears to be written in Chinese: $MISSPELLED_WORDS"
   fi
 
-  # Remove quoted text from FULL_COMMIT_MSG for spell checking.
-  MSG_FOR_SPELLCHECK=$(echo "$FULL_COMMIT_MSG" | sed -E "s/(['\"][^'\"]*['\"])//g")
+  # Remove quoted text and commit hashes from $FULL_COMMIT_MSG for spell checking.
+  # Handles commit references like "commit 7d05741" (short) or full 40-char hashes.
+  MSG_FOR_SPELLCHECK=$(echo "$FULL_COMMIT_MSG" | sed -E \
+    -e "s/(['\"][^'\"]*['\"])//g" \
+    -e "s/\bcommit[[:space:]]+[0-9a-fA-F]{7,40}\b/commit/g")
 
   # Use aspell to list misspelled words according to American English, ignoring quoted text.
   MISSPELLED_WORDS=$(echo "$MSG_FOR_SPELLCHECK" | $ASPELL --lang=en --list --home-dir=scripts --personal=aspell-pws)