[PATCH] git-fsck-cache: Gracefully handle non-commit IDs
[git.git] / diff-tree-helper.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "strbuf.h"
6 #include "diff.h"
7
8 static int matches_pathspec(const char *name, const char **spec, int cnt)
9 {
10         int i;
11         int namelen = strlen(name);
12         for (i = 0; i < cnt; i++) {
13                 int speclen = strlen(spec[i]);
14                 if (! strncmp(spec[i], name, speclen) &&
15                     speclen <= namelen &&
16                     (name[speclen] == 0 ||
17                      name[speclen] == '/'))
18                         return 1;
19         }
20         return 0;
21 }
22
23 static int parse_oneside_change(const char *cp, struct diff_spec *one,
24                                 char *path)
25 {
26         int ch;
27
28         one->file_valid = one->sha1_valid = 1;
29         one->mode = 0;
30         while ((ch = *cp) && '0' <= ch && ch <= '7') {
31                 one->mode = (one->mode << 3) | (ch - '0');
32                 cp++;
33         }
34
35         if (strncmp(cp, "\tblob\t", 6))
36                 return -1;
37         cp += 6;
38         if (get_sha1_hex(cp, one->u.sha1))
39                 return -1;
40         cp += 40;
41         if (*cp++ != '\t')
42                 return -1;
43         strcpy(path, cp);
44         return 0;
45 }
46
47 static int parse_diff_tree_output(const char *buf, const char **spec, int cnt)
48 {
49         struct diff_spec old, new;
50         char path[PATH_MAX];
51         const char *cp = buf;
52         int ch;
53
54         switch (*cp++) {
55         case 'U':
56                 if (!cnt || matches_pathspec(cp + 1, spec, cnt))
57                         diff_unmerge(cp + 1);
58                 return 0;
59         case '+':
60                 old.file_valid = 0;
61                 parse_oneside_change(cp, &new, path);
62                 break;
63         case '-':
64                 new.file_valid = 0;
65                 parse_oneside_change(cp, &old, path);
66                 break;
67         case '*':
68                 old.file_valid = old.sha1_valid =
69                         new.file_valid = new.sha1_valid = 1;
70                 old.mode = new.mode = 0;
71                 while ((ch = *cp) && ('0' <= ch && ch <= '7')) {
72                         old.mode = (old.mode << 3) | (ch - '0');
73                         cp++;
74                 }
75                 if (strncmp(cp, "->", 2))
76                         return -1;
77                 cp += 2;
78                 while ((ch = *cp) && ('0' <= ch && ch <= '7')) {
79                         new.mode = (new.mode << 3) | (ch - '0');
80                         cp++;
81                 }
82                 if (strncmp(cp, "\tblob\t", 6))
83                         return -1;
84                 cp += 6;
85                 if (get_sha1_hex(cp, old.u.sha1))
86                         return -1;
87                 cp += 40;
88                 if (strncmp(cp, "->", 2))
89                         return -1;
90                 cp += 2;
91                 if (get_sha1_hex(cp, new.u.sha1))
92                         return -1;
93                 cp += 40;
94                 if (*cp++ != '\t')
95                         return -1;
96                 strcpy(path, cp);
97                 break;
98         default:
99                 return -1;
100         }
101         if (!cnt || matches_pathspec(path, spec, cnt))
102                 run_external_diff(path, &old, &new);
103         return 0;
104 }
105
106 static const char *diff_tree_helper_usage =
107 "diff-tree-helper [-R] [-z] paths...";
108
109 int main(int ac, const char **av) {
110         struct strbuf sb;
111         int reverse_diff = 0;
112         int line_termination = '\n';
113
114         strbuf_init(&sb);
115
116         while (1 < ac && av[1][0] == '-') {
117                 if (av[1][1] == 'R')
118                         reverse_diff = 1;
119                 else if (av[1][1] == 'z')
120                         line_termination = 0;
121                 else
122                         usage(diff_tree_helper_usage);
123                 ac--; av++;
124         }
125         /* the remaining parameters are paths patterns */
126
127         while (1) {
128                 int status;
129                 read_line(&sb, stdin, line_termination);
130                 if (sb.eof)
131                         break;
132                 status = parse_diff_tree_output(sb.buf, av+1, ac-1);
133                 if (status)
134                         fprintf(stderr, "cannot parse %s\n", sb.buf);
135         }
136         return 0;
137 }