avoid computing zero offsets from NULL pointer
[git] / builtin / rerere.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "config.h"
4 #include "dir.h"
5 #include "parse-options.h"
6 #include "string-list.h"
7 #include "rerere.h"
8 #include "xdiff/xdiff.h"
9 #include "xdiff-interface.h"
10 #include "pathspec.h"
11
12 static const char * const rerere_usage[] = {
13         N_("git rerere [clear | forget <path>... | status | remaining | diff | gc]"),
14         NULL,
15 };
16
17 static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
18 {
19         int i;
20         for (i = 0; i < nbuf; i++)
21                 if (write_in_full(1, ptr[i].ptr, ptr[i].size) < 0)
22                         return -1;
23         return 0;
24 }
25
26 static int diff_two(const char *file1, const char *label1,
27                 const char *file2, const char *label2)
28 {
29         xpparam_t xpp;
30         xdemitconf_t xecfg;
31         xdemitcb_t ecb;
32         mmfile_t minus, plus;
33         int ret;
34
35         if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
36                 return -1;
37
38         printf("--- a/%s\n+++ b/%s\n", label1, label2);
39         fflush(stdout);
40         memset(&xpp, 0, sizeof(xpp));
41         xpp.flags = 0;
42         memset(&xecfg, 0, sizeof(xecfg));
43         xecfg.ctxlen = 3;
44         ecb.out_hunk = NULL;
45         ecb.out_line = outf;
46         ret = xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
47
48         free(minus.ptr);
49         free(plus.ptr);
50         return ret;
51 }
52
53 int cmd_rerere(int argc, const char **argv, const char *prefix)
54 {
55         struct string_list merge_rr = STRING_LIST_INIT_DUP;
56         int i, autoupdate = -1, flags = 0;
57
58         struct option options[] = {
59                 OPT_SET_INT(0, "rerere-autoupdate", &autoupdate,
60                         N_("register clean resolutions in index"), 1),
61                 OPT_END(),
62         };
63
64         argc = parse_options(argc, argv, prefix, options, rerere_usage, 0);
65
66         git_config(git_xmerge_config, NULL);
67
68         if (autoupdate == 1)
69                 flags = RERERE_AUTOUPDATE;
70         if (autoupdate == 0)
71                 flags = RERERE_NOAUTOUPDATE;
72
73         if (argc < 1)
74                 return repo_rerere(the_repository, flags);
75
76         if (!strcmp(argv[0], "forget")) {
77                 struct pathspec pathspec;
78                 if (argc < 2)
79                         warning(_("'git rerere forget' without paths is deprecated"));
80                 parse_pathspec(&pathspec, 0, PATHSPEC_PREFER_CWD,
81                                prefix, argv + 1);
82                 return rerere_forget(the_repository, &pathspec);
83         }
84
85         if (!strcmp(argv[0], "clear")) {
86                 rerere_clear(the_repository, &merge_rr);
87         } else if (!strcmp(argv[0], "gc"))
88                 rerere_gc(the_repository, &merge_rr);
89         else if (!strcmp(argv[0], "status")) {
90                 if (setup_rerere(the_repository, &merge_rr,
91                                  flags | RERERE_READONLY) < 0)
92                         return 0;
93                 for (i = 0; i < merge_rr.nr; i++)
94                         printf("%s\n", merge_rr.items[i].string);
95         } else if (!strcmp(argv[0], "remaining")) {
96                 rerere_remaining(the_repository, &merge_rr);
97                 for (i = 0; i < merge_rr.nr; i++) {
98                         if (merge_rr.items[i].util != RERERE_RESOLVED)
99                                 printf("%s\n", merge_rr.items[i].string);
100                         else
101                                 /* prepare for later call to
102                                  * string_list_clear() */
103                                 merge_rr.items[i].util = NULL;
104                 }
105         } else if (!strcmp(argv[0], "diff")) {
106                 if (setup_rerere(the_repository, &merge_rr,
107                                  flags | RERERE_READONLY) < 0)
108                         return 0;
109                 for (i = 0; i < merge_rr.nr; i++) {
110                         const char *path = merge_rr.items[i].string;
111                         const struct rerere_id *id = merge_rr.items[i].util;
112                         if (diff_two(rerere_path(id, "preimage"), path, path, path))
113                                 die(_("unable to generate diff for '%s'"), rerere_path(id, NULL));
114                 }
115         } else
116                 usage_with_options(rerere_usage, options);
117
118         string_list_clear(&merge_rr, 1);
119         return 0;
120 }