Re: [PATCH] make the sample pre-commit hook script reject names with newlines, too

Andreas Schwab wrote:

Jim Meyering [off-list ref] writes:

quoted

@@ -26,7 +29,7 @@ if [ "$allownonascii" != "true" ] &&
 	# even required, for portability to Solaris 10's /usr/bin/tr), since
 	# the square bracket bytes happen to fall in the designated range.
 	test "$(git diff --cached --name-only --diff-filter=A -z $against |
-	  LC_ALL=C tr -d '[ -~]\0')"
+	  LC_ALL=C tr -d '[ -~]\0' | wc -c)" != 0

This will fail if the output of wc contains leading spaces.

Good point.  Thanks.  That's a portability bug.
GNU wc outputs no leading spaces, but others certainly do.

Removing the double quotes fixes that:

-- >8 --
Subject: [PATCH] make the sample pre-commit hook script reject names with
 newlines, too

The sample pre-commit hook script would fail to reject a file name
like "a\nb" because of the way newlines are handled in "$(...)".
Adjust the test to count filtered bytes and require there be 0.
Also print all diagnostics to standard error, not stdout, so they
will actually be seen.

Signed-off-by: Jim Meyering <redacted>
---
 templates/hooks--pre-commit.sample |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/templates/hooks--pre-commit.sample b/templates/hooks--pre-commit.sample
index b187c4b..18c4829 100755
--- a/templates/hooks--pre-commit.sample
+++ b/templates/hooks--pre-commit.sample

@@ -18,6 +18,9 @@ fi
 # If you want to allow non-ascii filenames set this variable to true.
 allownonascii=$(git config hooks.allownonascii)

+# Redirect output to stderr.
+exec 1>&2
+
 # Cross platform projects tend to avoid non-ascii filenames; prevent
 # them from being added to the repository. We exploit the fact that the
 # printable range starts at the space character and ends with tilde.

@@ -25,8 +28,8 @@ if [ "$allownonascii" != "true" ] &&
 	# Note that the use of brackets around a tr range is ok here, (it's
 	# even required, for portability to Solaris 10's /usr/bin/tr), since
 	# the square bracket bytes happen to fall in the designated range.
-	test "$(git diff --cached --name-only --diff-filter=A -z $against |
-	  LC_ALL=C tr -d '[ -~]\0')"
+	test $(git diff --cached --name-only --diff-filter=A -z $against |
+	  LC_ALL=C tr -d '[ -~]\0' | wc -c) != 0
 then
 	echo "Error: Attempt to add a non-ascii file name."
 	echo

@@ -43,4 +46,5 @@ then
 	exit 1
 fi

+# If there are whitespace errors, print the offending file names and fail.
 exec git diff-index --check --cached $against --
--

1.7.7.419.g87009