Allow git-merge not to commit.
[git.git] / patch-id.c
1 #include "cache.h"
2
3 static void flush_current_id(int patchlen, unsigned char *id, SHA_CTX *c)
4 {
5         unsigned char result[20];
6         char name[50];
7
8         if (!patchlen)
9                 return;
10
11         SHA1_Final(result, c);
12         memcpy(name, sha1_to_hex(id), 41);
13         printf("%s %s\n", sha1_to_hex(result), name);
14         SHA1_Init(c);
15 }
16
17 static int remove_space(char *line)
18 {
19         char *src = line;
20         char *dst = line;
21         unsigned char c;
22
23         while ((c = *src++) != '\0') {
24                 if (!isspace(c))
25                         *dst++ = c;
26         }
27         return dst - line;
28 }
29
30 static void generate_id_list(void)
31 {
32         static unsigned char sha1[20];
33         static char line[1000];
34         SHA_CTX ctx;
35         int patchlen = 0;
36
37         SHA1_Init(&ctx);
38         while (fgets(line, sizeof(line), stdin) != NULL) {
39                 unsigned char n[20];
40                 char *p = line;
41                 int len;
42
43                 if (!memcmp(line, "diff-tree ", 10))
44                         p += 10;
45
46                 if (!get_sha1_hex(p, n)) {
47                         flush_current_id(patchlen, sha1, &ctx);
48                         memcpy(sha1, n, 20);
49                         patchlen = 0;
50                         continue;
51                 }
52
53                 /* Ignore commit comments */
54                 if (!patchlen && memcmp(line, "diff ", 5))
55                         continue;
56
57                 /* Ignore git-diff index header */
58                 if (!memcmp(line, "index ", 6))
59                         continue;
60
61                 /* Ignore line numbers when computing the SHA1 of the patch */
62                 if (!memcmp(line, "@@ -", 4))
63                         continue;
64
65                 /* Compute the sha without whitespace */
66                 len = remove_space(line);
67                 patchlen += len;
68                 SHA1_Update(&ctx, line, len);
69         }
70         flush_current_id(patchlen, sha1, &ctx);
71 }
72
73 static const char patch_id_usage[] = "git-patch-id < patch";
74
75 int main(int argc, char **argv)
76 {
77         if (argc != 1)
78                 usage(patch_id_usage);
79
80         generate_id_list();
81         return 0;
82 }