archive-tar: report wrong pax extended header length

Extended header entries contain a length value that is a bit tricky to
calculate because it includes its own length (number of decimal digits)
as well.  We get it wrong in corner cases.  Add a check, report wrong
results as a warning and add a test for exercising it.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/archive-tar.c b/archive-tar.c
index 4aabd566fbb8af7065ebe8fa62afe8e8e70abe04..181da4e843bbc42d7bf3394181996f67e279a4bb 100644 (file)
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -144,6 +144,7 @@ static int stream_blocked(const struct object_id *oid)
 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
                                     const char *value, unsigned int valuelen)
 {
+       size_t orig_len = sb->len;
        int len, tmp;
 
        /* "%u %s=%s\n" */
@@ -155,6 +156,11 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
        strbuf_addf(sb, "%u %s=", len, keyword);
        strbuf_add(sb, value, valuelen);
        strbuf_addch(sb, '\n');
+
+       if (len != sb->len - orig_len)
+               warning("pax extended header length miscalculated as %d"
+                       ", should be %"PRIuMAX,
+                       len, (uintmax_t)(sb->len - orig_len));
 }
 
 /*

diff --git a/t/t5004-archive-corner-cases.sh b/t/t5004-archive-corner-cases.sh
index 271eb5a1fdfbfe4aab216271fc1897968283639d..2f15d1899dc5646849876cdd9bd2fd9bccfb2a4f 100755 (executable)
--- a/t/t5004-archive-corner-cases.sh
+++ b/t/t5004-archive-corner-cases.sh
@@ -204,4 +204,24 @@ test_expect_success EXPENSIVE,LONG_IS_64BIT,UNZIP,UNZIP_ZIP64_SUPPORT,ZIPINFO \
        grep $size big.lst
 '
 
+build_tree() {
+       perl -e '
+               my $hash = $ARGV[0];
+               foreach my $order (2..6) {
+                       $first = 10 ** $order;
+                       foreach my $i (-13..-9) {
+                               my $name = "a" x ($first + $i);
+                               print "100644 blob $hash\t$name\n"
+                       }
+               }
+       ' "$1"
+}
+
+test_expect_failure 'tar archive with long paths' '
+       blob=$(echo foo | git hash-object -w --stdin) &&
+       tree=$(build_tree $blob | git mktree) &&
+       git archive -o long_paths.tar $tree 2>stderr &&
+       test_must_be_empty stderr
+'
+
 test_done