pre-commit: Ignore missing pre-commit-ignore.py

Print error message to stderr and return non-zero exit status from
child process.

Change-Id: Icd433d79c5a7bf8b6ddd8e94e26695b353e34d1f
Reviewed-on: https://code.wireshark.org/review/17116
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: João Valverde <j@v6e.pt>
Reviewed-by: João Valverde <j@v6e.pt>

2 files changed, 5 insertions, 10 deletions

diff --git a/tools/pre-commit b/tools/pre-commit
index 35895a4cf1..b5a7d8eab4 100755
--- a/tools/pre-commit
+++ b/tools/pre-commit
@@ -55,14 +55,10 @@ COMMIT_FILES=`git diff-index --cached --name-status ${COMMIT_ID} | grep -v "^D"
 filter_script=${PWD}/tools/pre-commit-ignore.py
 filter_conf=${PWD}/tools/pre-commit-ignore.conf
 
-if [ ! -e "$filter_script" ]; then
-    echo "File '$filter_script' does not exist. Aborting."
-    exit 1
-fi
-
-CHECK_FILES=`echo "$COMMIT_FILES" | "$PYBIN" "$filter_script" "$filter_conf"`
-if [ $? -ne 0 ]; then
-    exit 1
+if [ -f "$filter_script" ] && [ -f "$filter_conf" ]; then
+    CHECK_FILES=`echo "$COMMIT_FILES" | "$PYBIN" "$filter_script" "$filter_conf"` || exit
+else
+    CHECK_FILES="$COMMIT_FILES"
 fi
 
 # On windows python will output \r\n line endings - we don't want that.
diff --git a/tools/pre-commit-ignore.py b/tools/pre-commit-ignore.py
index d043368a95..e55d42b949 100755
--- a/tools/pre-commit-ignore.py
+++ b/tools/pre-commit-ignore.py
@@ -40,8 +40,7 @@ def load_checkignore(path):
         with open(path) as f:
             patterns = f.read()
     except OSError as err:
-        print(str(err))
-        return []
+        sys.exit(str(err))
     ign = [l.strip() for l in patterns.splitlines()]
     ign = [l for l in ign if l and not l.startswith("#")]
     return ign