patch-id.con commit [PATCH] git-branch: avoid getting confused by empty or nonexisting branches. (a38e727)
   1#include <ctype.h>
   2#include "cache.h"
   3
   4static void flush_current_id(int patchlen, unsigned char *id, SHA_CTX *c)
   5{
   6        unsigned char result[20];
   7        char name[50];
   8
   9        if (!patchlen)
  10                return;
  11
  12        SHA1_Final(result, c);
  13        memcpy(name, sha1_to_hex(id), 41);
  14        printf("%s %s\n", sha1_to_hex(result), name);
  15        SHA1_Init(c);
  16}
  17
  18static int remove_space(char *line)
  19{
  20        char *src = line;
  21        char *dst = line;
  22        unsigned char c;
  23
  24        while ((c = *src++) != '\0') {
  25                if (!isspace(c))
  26                        *dst++ = c;
  27        }
  28        return dst - line;
  29}
  30
  31static void generate_id_list(void)
  32{
  33        static unsigned char sha1[20];
  34        static char line[1000];
  35        SHA_CTX ctx;
  36        int patchlen = 0;
  37
  38        SHA1_Init(&ctx);
  39        while (fgets(line, sizeof(line), stdin) != NULL) {
  40                unsigned char n[20];
  41                char *p = line;
  42                int len;
  43
  44                if (!memcmp(line, "diff-tree ", 10))
  45                        p += 10;
  46
  47                if (!get_sha1_hex(p, n)) {
  48                        flush_current_id(patchlen, sha1, &ctx);
  49                        memcpy(sha1, n, 20);
  50                        patchlen = 0;
  51                        continue;
  52                }
  53
  54                /* Ignore commit comments */
  55                if (!patchlen && memcmp(line, "diff ", 5))
  56                        continue;
  57
  58                /* Ignore line numbers when computing the SHA1 of the patch */
  59                if (!memcmp(line, "@@ -", 4))
  60                        continue;
  61
  62                /* Compute the sha without whitespace */
  63                len = remove_space(line);
  64                patchlen += len;
  65                SHA1_Update(&ctx, line, len);
  66        }
  67        flush_current_id(patchlen, sha1, &ctx);
  68}
  69
  70static const char patch_id_usage[] = "usage: git-patch-id < patch";
  71
  72int main(int argc, char **argv)
  73{
  74        if (argc != 1)
  75                usage(patch_id_usage);
  76
  77        generate_id_list();
  78        return 0;
  79}