merge-blobs.c

   1 #include "git-compat-util.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         enum ll_merge_result 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         if (merge_status == LL_MERGE_BINARY_CONFLICT)
  54                 warning("Cannot merge binary files: %s (%s vs. %s)",
  55                         path, ".our", ".their");
  56
  57         *size = res.size;
  58         return res.ptr;
  59 }
  60
  61 void *merge_blobs(struct index_state *istate, const char *path,
  62                   struct blob *base, struct blob *our,
  63                   struct blob *their, unsigned long *size)
  64 {
  65         void *res = NULL;
  66         mmfile_t f1, f2, common;
  67
  68         /*
  69          * Removed in either branch?
  70          *
  71          * NOTE! This depends on the caller having done the
  72          * proper warning about removing a file that got
  73          * modified in the other branch!
  74          */
  75         if (!our || !their) {
  76                 enum object_type type;
  77                 if (base)
  78                         return NULL;
  79                 if (!our)
  80                         our = their;
  81                 return read_object_file(&our->object.oid, &type, size);
  82         }
  83
  84         if (fill_mmfile_blob(&f1, our) < 0)
  85                 goto out_no_mmfile;
  86         if (fill_mmfile_blob(&f2, their) < 0)
  87                 goto out_free_f1;
  88
  89         if (base) {
  90                 if (fill_mmfile_blob(&common, base) < 0)
  91                         goto out_free_f2_f1;
  92         } else {
  93                 common.ptr = xstrdup("");
  94                 common.size = 0;
  95         }
  96         res = three_way_filemerge(istate, path, &common, &f1, &f2, size);
  97         free_mmfile(&common);
  98 out_free_f2_f1:
  99         free_mmfile(&f2);
 100 out_free_f1:
 101         free_mmfile(&f1);
 102 out_no_mmfile:
 103         return res;
 104 }