merge with /dev/null as base, instead of punting O==empty case

diff --git a/patch-id.c b/patch-id.c
index 0bd640cc481eddc72e37a864b115f4d6ba7883b1..edbc4aa3e82974168f2d4c21085bdd43b774d55e 100644 (file)
--- a/patch-id.c
+++ b/patch-id.c
@@ -1,4 +1,3 @@
-#include <ctype.h>
 #include "cache.h"
 
 static void flush_current_id(int patchlen, unsigned char *id, SHA_CTX *c)
@@ -55,6 +54,10 @@ static void generate_id_list(void)
                if (!patchlen && memcmp(line, "diff ", 5))
                        continue;
 
+               /* Ignore git-diff index header */
+               if (!memcmp(line, "index ", 6))
+                       continue;
+
                /* Ignore line numbers when computing the SHA1 of the patch */
                if (!memcmp(line, "@@ -", 4))
                        continue;
@@ -67,7 +70,7 @@ static void generate_id_list(void)
        flush_current_id(patchlen, sha1, &ctx);
 }
 
-static const char patch_id_usage[] = "usage: git-patch-id < patch";
+static const char patch_id_usage[] = "git-patch-id < patch";
 
 int main(int argc, char **argv)
 {