archive-tar: report wrong pax extended header length

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));
 }
 
 /*