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
   8 static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
   9 {
  10         void *buf;
  11         unsigned long size;
  12         enum object_type type;
  13
  14         buf = read_sha1_file(obj->object.oid.hash, &type, &size);
  15         if (!buf)
  16                 return -1;
  17         if (type != OBJ_BLOB) {
  18                 free(buf);
  19                 return -1;
  20         }
  21         f->ptr = buf;
  22         f->size = size;
  23         return 0;
  24 }
  25
  26 static void free_mmfile(mmfile_t *f)
  27 {
  28         free(f->ptr);
  29 }
  30
  31 static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
  32 {
  33         int merge_status;
  34         mmbuffer_t res;
  35
  36         /*
  37          * This function is only used by cmd_merge_tree, which
  38          * does not respect the merge.conflictstyle option.
  39          * There is no need to worry about a label for the
  40          * common ancestor.
  41          */
  42         merge_status = ll_merge(&res, path, base, NULL,
  43                                 our, ".our", their, ".their", NULL);
  44         if (merge_status < 0)
  45                 return NULL;
  46
  47         *size = res.size;
  48         return res.ptr;
  49 }
  50
  51 void *merge_blobs(const char *path, struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
  52 {
  53         void *res = NULL;
  54         mmfile_t f1, f2, common;
  55
  56         /*
  57          * Removed in either branch?
  58          *
  59          * NOTE! This depends on the caller having done the
  60          * proper warning about removing a file that got
  61          * modified in the other branch!
  62          */
  63         if (!our || !their) {
  64                 enum object_type type;
  65                 if (base)
  66                         return NULL;
  67                 if (!our)
  68                         our = their;
  69                 return read_sha1_file(our->object.oid.hash, &type, size);
  70         }
  71
  72         if (fill_mmfile_blob(&f1, our) < 0)
  73                 goto out_no_mmfile;
  74         if (fill_mmfile_blob(&f2, their) < 0)
  75                 goto out_free_f1;
  76
  77         if (base) {
  78                 if (fill_mmfile_blob(&common, base) < 0)
  79                         goto out_free_f2_f1;
  80         } else {
  81                 common.ptr = xstrdup("");
  82                 common.size = 0;
  83         }
  84         res = three_way_filemerge(path, &common, &f1, &f2, size);
  85         free_mmfile(&common);
  86 out_free_f2_f1:
  87         free_mmfile(&f2);
  88 out_free_f1:
  89         free_mmfile(&f1);
  90 out_no_mmfile:
  91         return res;
  92 }