Re: [PATCH v3] test-lib.sh: do not "echo" externally supplied strings

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 18, 2014, 18:47 UTC
Message-ID: <xmqqvbvb8ht7.fsf@gitster.dls.corp.google.com>
In-Reply-To: <20140318001410.GA4813@ibr.ch>

Uwe Storbeck <uwe@ibr.ch> writes:

Show 11 quoted lines

> In some places we "echo" a string that is supplied by the calling
> test script and may contain backslash sequences. The echo command
> of some shells, most notably "dash", interprets these backslash
> sequences (POSIX.1 allows this) which may scramble the test
> output.
>
> Signed-off-by: Uwe Storbeck <uwe@ibr.ch>
> ---
>
> Commit message rewritten to avoid title continuation in the body.
> Thanks Junio C Hamano for the hint.

Here is what I queued yesterday. I was wrong to say "control characters"; a backslash sequence is not necessarily a control character (e.g. \c at the end that suppresses the final LF), so I'll replace it with your version.

The test titles are not externally supplied but under our control, so it is less problematic than the "rebase -i" case where we do get bitten by user supplied commit title string. Still it is a good idea to apply this change to protect ourselves.

Thanks.

commit 215cd588caebe86fe77115bdda97930b4659aecd
Author: Uwe Storbeck <uwe@ibr.ch>
Date:   Sat Mar 15 00:57:36 2014 +0100

    test-lib.sh: do not "echo" test titles
    
    The test title could be a string with backslash in it, and can be
    interpreted as control characters by the echo command of some shells
    (e.g. dash).
    
    Signed-off-by: Uwe Storbeck <uwe@ibr.ch>
    Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 1531c24..3c7cb1d 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -277,7 +277,7 @@ error "Test script did not set test_description."
 
 if test "$help" = "t"
 then
-	echo "$test_description"
+	printf '%s\n' "$test_description"
 	exit 0
 fi
 
@@ -328,7 +328,7 @@ test_failure_ () {
 	test_failure=$(($test_failure + 1))
 	say_color error "not ok $test_count - $1"
 	shift
-	echo "$@" | sed -e 's/^/#	/'
+	printf '%s\n' "$*" | sed -e 's/^/#	/'
 	test "$immediate" = "" || { GIT_EXIT_OK=t; exit 1; }
 }