perf: add test for writing the index

diff --git a/builtin/get-tar-commit-id.c b/builtin/get-tar-commit-id.c
index aa72596083d4e7ad9b84058e8b23b09849d74d7c..e21c5416cd478eab3b0dddcba5ca9eeefad83d34 100644 (file)
--- a/builtin/get-tar-commit-id.c
+++ b/builtin/get-tar-commit-id.c
@@ -8,7 +8,7 @@
 #include "quote.h"
 
 static const char builtin_get_tar_commit_id_usage[] =
-"git get-tar-commit-id < <tarfile>";
+"git get-tar-commit-id";
 
 /* ustar header + extended global header content */
 #define RECORDSIZE     (512)
@@ -19,6 +19,7 @@ int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
        char buffer[HEADERSIZE];
        struct ustar_header *header = (struct ustar_header *)buffer;
        char *content = buffer + RECORDSIZE;
+       const char *comment;
        ssize_t n;
 
        if (argc != 1)
@@ -29,10 +30,10 @@ int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
                die("git get-tar-commit-id: read error");
        if (header->typeflag[0] != 'g')
                return 1;
-       if (memcmp(content, "52 comment=", 11))
+       if (!skip_prefix(content, "52 comment=", &comment))
                return 1;
 
-       n = write_in_full(1, content + 11, 41);
+       n = write_in_full(1, comment, 41);
        if (n < 41)
                die_errno("git get-tar-commit-id: write error");