sscanf/strtoul: parse integers robustly

diff --git a/commit.c b/commit.c
index a4f2e74c0b9b17a467fd9c4d3f5a2d275d5ea038..754d1b8a0b8282fd3d1d6bd8f6ccb21b407504a5 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -654,6 +654,7 @@ static char *get_header(const struct commit *commit, const char *key)
 static char *replace_encoding_header(char *buf, const char *encoding)
 {
        char *encoding_header = strstr(buf, "\nencoding ");
+       char *header_end = strstr(buf, "\n\n");
        char *end_of_encoding_header;
        int encoding_header_pos;
        int encoding_header_len;
@@ -661,8 +662,10 @@ static char *replace_encoding_header(char *buf, const char *encoding)
        int need_len;
        int buflen = strlen(buf) + 1;
 
-       if (!encoding_header)
-               return buf; /* should not happen but be defensive */
+       if (!header_end)
+               header_end = buf + buflen;
+       if (!encoding_header || encoding_header >= header_end)
+               return buf;
        encoding_header++;
        end_of_encoding_header = strchr(encoding_header, '\n');
        if (!end_of_encoding_header)