checkout --conflict=diff3: add a label for ancestor
[git/git.git] / merge-file.c
CommitLineData
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1#include "cache.h"
2#include "run-command.h"
3#include "xdiff-interface.h"
15b4f7a6 4#include "ll-merge.h"
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5#include "blob.h"
6
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7static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
8{
9 void *buf;
10 unsigned long size;
21666f1a 11 enum object_type type;
0c799383 12
21666f1a 13 buf = read_sha1_file(obj->object.sha1, &type, &size);
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14 if (!buf)
15 return -1;
21666f1a 16 if (type != OBJ_BLOB)
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17 return -1;
18 f->ptr = buf;
19 f->size = size;
20 return 0;
21}
22
23static void free_mmfile(mmfile_t *f)
24{
25 free(f->ptr);
26}
27
15b4f7a6 28static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
0c799383 29{
e2b70087 30 int merge_status;
15b4f7a6 31 mmbuffer_t res;
0c799383 32
f01de62e 33 merge_status = ll_merge(&res, path, base, NULL,
15b4f7a6 34 our, ".our", their, ".their", 0);
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35 if (merge_status < 0)
36 return NULL;
37
38 *size = res.size;
39 return res.ptr;
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40}
41
42static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)
43{
44 int i;
45 mmfile_t *dst = priv_;
46
47 for (i = 0; i < nbuf; i++) {
48 memcpy(dst->ptr + dst->size, mb[i].ptr, mb[i].size);
49 dst->size += mb[i].size;
50 }
51 return 0;
52}
53
54static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
55{
56 unsigned long size = f1->size < f2->size ? f1->size : f2->size;
57 void *ptr = xmalloc(size);
58 xpparam_t xpp;
59 xdemitconf_t xecfg;
60 xdemitcb_t ecb;
61
9ccd0a88 62 memset(&xpp, 0, sizeof(xpp));
0c799383 63 xpp.flags = XDF_NEED_MINIMAL;
30b25010 64 memset(&xecfg, 0, sizeof(xecfg));
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65 xecfg.ctxlen = 3;
66 xecfg.flags = XDL_EMIT_COMMON;
67 ecb.outf = common_outf;
68
69 res->ptr = ptr;
70 res->size = 0;
71
72 ecb.priv = res;
c279d7e9 73 return xdi_diff(f1, f2, &xpp, &xecfg, &ecb);
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74}
75
15b4f7a6 76void *merge_file(const char *path, struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
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77{
78 void *res = NULL;
79 mmfile_t f1, f2, common;
80
81 /*
82 * Removed in either branch?
83 *
84 * NOTE! This depends on the caller having done the
85 * proper warning about removing a file that got
86 * modified in the other branch!
87 */
88 if (!our || !their) {
21666f1a 89 enum object_type type;
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90 if (base)
91 return NULL;
92 if (!our)
93 our = their;
21666f1a 94 return read_sha1_file(our->object.sha1, &type, size);
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95 }
96
97 if (fill_mmfile_blob(&f1, our) < 0)
98 goto out_no_mmfile;
99 if (fill_mmfile_blob(&f2, their) < 0)
100 goto out_free_f1;
101
102 if (base) {
103 if (fill_mmfile_blob(&common, base) < 0)
104 goto out_free_f2_f1;
105 } else {
106 if (generate_common_file(&common, &f1, &f2) < 0)
107 goto out_free_f2_f1;
108 }
15b4f7a6 109 res = three_way_filemerge(path, &common, &f1, &f2, size);
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110 free_mmfile(&common);
111out_free_f2_f1:
112 free_mmfile(&f2);
113out_free_f1:
114 free_mmfile(&f1);
115out_no_mmfile:
116 return res;
117}