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>

René Scharfe committed Aug 17, 2019 at 18:23 UTC 4060c1990a9cceb710808bd4b4ab94d2355aefff
2 files changed +26
archive-tar.c
+6
@@ -144,6 +144,7 @@ static int stream_blocked(const struct object_id *oid)
144 static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
145 const char *value, unsigned int valuelen)
146 {
147 + size_t orig_len = sb->len;
148 int len, tmp;
149
150 /* "%u %s=%s\n" */
@@ -155,6 +156,11 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
156 strbuf_addf(sb, "%u %s=", len, keyword);
157 strbuf_add(sb, value, valuelen);
158 strbuf_addch(sb, '\n');
159 +
160 + if (len != sb->len - orig_len)
161 + warning("pax extended header length miscalculated as %d"
162 + ", should be %"PRIuMAX,
163 + len, (uintmax_t)(sb->len - orig_len));
164 }
165
166 /*
t/t5004-archive-corner-cases.sh
+20
@@ -204,4 +204,24 @@ test_expect_success EXPENSIVE,LONG_IS_64BIT,UNZIP,UNZIP_ZIP64_SUPPORT,ZIPINFO \
204 grep $size big.lst
205 '
206
207 +build_tree() {
208 + perl -e '
209 + my $hash = $ARGV[0];
210 + foreach my $order (2..6) {
211 + $first = 10 ** $order;
212 + foreach my $i (-13..-9) {
213 + my $name = "a" x ($first + $i);
214 + print "100644 blob $hash\t$name\n"
215 + }
216 + }
217 + ' "$1"
218 +}
219 +
220 +test_expect_failure 'tar archive with long paths' '
221 + blob=$(echo foo | git hash-object -w --stdin) &&
222 + tree=$(build_tree $blob | git mktree) &&
223 + git archive -o long_paths.tar $tree 2>stderr &&
224 + test_must_be_empty stderr
225 +'
226 +
227 test_done