t4014: stop losing return codes of git commands
[git] / builtin / patch-id.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "diff.h"
4
5 static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result)
6 {
7         char name[50];
8
9         if (!patchlen)
10                 return;
11
12         memcpy(name, oid_to_hex(id), GIT_SHA1_HEXSZ + 1);
13         printf("%s %s\n", oid_to_hex(result), name);
14 }
15
16 static int remove_space(char *line)
17 {
18         char *src = line;
19         char *dst = line;
20         unsigned char c;
21
22         while ((c = *src++) != '\0') {
23                 if (!isspace(c))
24                         *dst++ = c;
25         }
26         return dst - line;
27 }
28
29 static int scan_hunk_header(const char *p, int *p_before, int *p_after)
30 {
31         static const char digits[] = "0123456789";
32         const char *q, *r;
33         int n;
34
35         q = p + 4;
36         n = strspn(q, digits);
37         if (q[n] == ',') {
38                 q += n + 1;
39                 n = strspn(q, digits);
40         }
41         if (n == 0 || q[n] != ' ' || q[n+1] != '+')
42                 return 0;
43
44         r = q + n + 2;
45         n = strspn(r, digits);
46         if (r[n] == ',') {
47                 r += n + 1;
48                 n = strspn(r, digits);
49         }
50         if (n == 0)
51                 return 0;
52
53         *p_before = atoi(q);
54         *p_after = atoi(r);
55         return 1;
56 }
57
58 static int get_one_patchid(struct object_id *next_oid, struct object_id *result,
59                            struct strbuf *line_buf, int stable)
60 {
61         int patchlen = 0, found_next = 0;
62         int before = -1, after = -1;
63         git_SHA_CTX ctx;
64
65         git_SHA1_Init(&ctx);
66         oidclr(result);
67
68         while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
69                 char *line = line_buf->buf;
70                 const char *p = line;
71                 int len;
72
73                 if (!skip_prefix(line, "diff-tree ", &p) &&
74                     !skip_prefix(line, "commit ", &p) &&
75                     !skip_prefix(line, "From ", &p) &&
76                     starts_with(line, "\\ ") && 12 < strlen(line))
77                         continue;
78
79                 if (!get_oid_hex(p, next_oid)) {
80                         found_next = 1;
81                         break;
82                 }
83
84                 /* Ignore commit comments */
85                 if (!patchlen && !starts_with(line, "diff "))
86                         continue;
87
88                 /* Parsing diff header?  */
89                 if (before == -1) {
90                         if (starts_with(line, "index "))
91                                 continue;
92                         else if (starts_with(line, "--- "))
93                                 before = after = 1;
94                         else if (!isalpha(line[0]))
95                                 break;
96                 }
97
98                 /* Looking for a valid hunk header?  */
99                 if (before == 0 && after == 0) {
100                         if (starts_with(line, "@@ -")) {
101                                 /* Parse next hunk, but ignore line numbers.  */
102                                 scan_hunk_header(line, &before, &after);
103                                 continue;
104                         }
105
106                         /* Split at the end of the patch.  */
107                         if (!starts_with(line, "diff "))
108                                 break;
109
110                         /* Else we're parsing another header.  */
111                         if (stable)
112                                 flush_one_hunk(result, &ctx);
113                         before = after = -1;
114                 }
115
116                 /* If we get here, we're inside a hunk.  */
117                 if (line[0] == '-' || line[0] == ' ')
118                         before--;
119                 if (line[0] == '+' || line[0] == ' ')
120                         after--;
121
122                 /* Compute the sha without whitespace */
123                 len = remove_space(line);
124                 patchlen += len;
125                 git_SHA1_Update(&ctx, line, len);
126         }
127
128         if (!found_next)
129                 oidclr(next_oid);
130
131         flush_one_hunk(result, &ctx);
132
133         return patchlen;
134 }
135
136 static void generate_id_list(int stable)
137 {
138         struct object_id oid, n, result;
139         int patchlen;
140         struct strbuf line_buf = STRBUF_INIT;
141
142         oidclr(&oid);
143         while (!feof(stdin)) {
144                 patchlen = get_one_patchid(&n, &result, &line_buf, stable);
145                 flush_current_id(patchlen, &oid, &result);
146                 oidcpy(&oid, &n);
147         }
148         strbuf_release(&line_buf);
149 }
150
151 static const char patch_id_usage[] = "git patch-id [--stable | --unstable]";
152
153 static int git_patch_id_config(const char *var, const char *value, void *cb)
154 {
155         int *stable = cb;
156
157         if (!strcmp(var, "patchid.stable")) {
158                 *stable = git_config_bool(var, value);
159                 return 0;
160         }
161
162         return git_default_config(var, value, cb);
163 }
164
165 int cmd_patch_id(int argc, const char **argv, const char *prefix)
166 {
167         int stable = -1;
168
169         git_config(git_patch_id_config, &stable);
170
171         /* If nothing is set, default to unstable. */
172         if (stable < 0)
173                 stable = 0;
174
175         if (argc == 2 && !strcmp(argv[1], "--stable"))
176                 stable = 1;
177         else if (argc == 2 && !strcmp(argv[1], "--unstable"))
178                 stable = 0;
179         else if (argc != 1)
180                 usage(patch_id_usage);
181
182         generate_id_list(stable);
183         return 0;
184 }