archive-tar: fix pax extended header length calculation
authorRené Scharfe <l.s.r@web.de>
Sat, 17 Aug 2019 16:24:01 +0000 (18:24 +0200)
committerJunio C Hamano <gitster@pobox.com>
Mon, 19 Aug 2019 17:48:02 +0000 (10:48 -0700)
A pax extended header record starts with a decimal number. Its value
is the length of the whole record, including its own length.

The calculation of that number in strbuf_append_ext_header() is off by
one in case the length of the rest is close to a higher order of
magnitude. This affects paths and link targets a bit shorter than 1000,
10000, 100000 etc. characters -- paths with a length of up to 100 fit
into the tar header and don't need a pax extended header.

The mistake has been present since the function was added by ae64bbc18c
("tar-tree: Introduce write_entry()", 2006-03-25).

Account for digits added to len during the loop and keep incrementing
until we have enough space for len and the rest. The crucial change is
to check against the current value of len before each iteration, instead
of against its value before the loop.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
archive-tar.c
t/t5004-archive-corner-cases.sh
index 181da4e843bbc42d7bf3394181996f67e279a4bb..3d76977c3f955ded0ecea03b80ad160eba917ade 100644 (file)
@@ -149,7 +149,7 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
 
        /* "%u %s=%s\n" */
        len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
-       for (tmp = len; tmp > 9; tmp /= 10)
+       for (tmp = 1; len / 10 >= tmp; tmp *= 10)
                len++;
 
        strbuf_grow(sb, len);
index 2f15d1899dc5646849876cdd9bd2fd9bccfb2a4f..4966a74b4d083f5dfedaaf3c8873d1c06f0a7fac 100755 (executable)
@@ -217,7 +217,7 @@ build_tree() {
        ' "$1"
 }
 
-test_expect_failure 'tar archive with long paths' '
+test_expect_success 'tar archive with long paths' '
        blob=$(echo foo | git hash-object -w --stdin) &&
        tree=$(build_tree $blob | git mktree) &&
        git archive -o long_paths.tar $tree 2>stderr &&