subtree: t7900: rename last_commit_message to last_commit_subject
[git] / merge-blobs.c
1 #include "cache.h"
2 #include "run-command.h"
3 #include "xdiff-interface.h"
4 #include "ll-merge.h"
5 #include "blob.h"
6 #include "merge-blobs.h"
7 #include "object-store.h"
8
9 static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
10 {
11         void *buf;
12         unsigned long size;
13         enum object_type type;
14
15         buf = read_object_file(&obj->object.oid, &type, &size);
16         if (!buf)
17                 return -1;
18         if (type != OBJ_BLOB) {
19                 free(buf);
20                 return -1;
21         }
22         f->ptr = buf;
23         f->size = size;
24         return 0;
25 }
26
27 static void free_mmfile(mmfile_t *f)
28 {
29         free(f->ptr);
30 }
31
32 static void *three_way_filemerge(struct index_state *istate,
33                                  const char *path,
34                                  mmfile_t *base,
35                                  mmfile_t *our,
36                                  mmfile_t *their,
37                                  unsigned long *size)
38 {
39         int merge_status;
40         mmbuffer_t res;
41
42         /*
43          * This function is only used by cmd_merge_tree, which
44          * does not respect the merge.conflictstyle option.
45          * There is no need to worry about a label for the
46          * common ancestor.
47          */
48         merge_status = ll_merge(&res, path, base, NULL,
49                                 our, ".our", their, ".their",
50                                 istate, NULL);
51         if (merge_status < 0)
52                 return NULL;
53
54         *size = res.size;
55         return res.ptr;
56 }
57
58 void *merge_blobs(struct index_state *istate, const char *path,
59                   struct blob *base, struct blob *our,
60                   struct blob *their, unsigned long *size)
61 {
62         void *res = NULL;
63         mmfile_t f1, f2, common;
64
65         /*
66          * Removed in either branch?
67          *
68          * NOTE! This depends on the caller having done the
69          * proper warning about removing a file that got
70          * modified in the other branch!
71          */
72         if (!our || !their) {
73                 enum object_type type;
74                 if (base)
75                         return NULL;
76                 if (!our)
77                         our = their;
78                 return read_object_file(&our->object.oid, &type, size);
79         }
80
81         if (fill_mmfile_blob(&f1, our) < 0)
82                 goto out_no_mmfile;
83         if (fill_mmfile_blob(&f2, their) < 0)
84                 goto out_free_f1;
85
86         if (base) {
87                 if (fill_mmfile_blob(&common, base) < 0)
88                         goto out_free_f2_f1;
89         } else {
90                 common.ptr = xstrdup("");
91                 common.size = 0;
92         }
93         res = three_way_filemerge(istate, path, &common, &f1, &f2, size);
94         free_mmfile(&common);
95 out_free_f2_f1:
96         free_mmfile(&f2);
97 out_free_f1:
98         free_mmfile(&f1);
99 out_no_mmfile:
100         return res;
101 }