Merge branch 'bw/union-merge-refactor'

* bw/union-merge-refactor:
  merge-file: add option to select union merge favor
  merge-file: add option to specify the marker size
  refactor merge flags into xmparam_t
  make union merge an xdl merge favor

diff --cc builtin/merge-file.c
index 1e70073a7ed022675031706a8e9f8c57ff3aa2a9,0000000000000000000000000000000000000000..69cc683332a04ddc6959fcef3d2853ccfb2860b8
mode 100644,000000..100644
--- 1/builtin/merge-file.c
--- /dev/null
+++ b/builtin/merge-file.c
@@@ -1,96 -1,0 +1,101 @@@
-       int level = XDL_MERGE_ZEALOUS_ALNUM;
-       int style = 0, quiet = 0;
-       int favor = 0;
 +#include "builtin.h"
 +#include "cache.h"
 +#include "xdiff/xdiff.h"
 +#include "xdiff-interface.h"
 +#include "parse-options.h"
 +
 +static const char *const merge_file_usage[] = {
 +      "git merge-file [options] [-L name1 [-L orig [-L name2]]] file1 orig_file file2",
 +      NULL
 +};
 +
 +static int label_cb(const struct option *opt, const char *arg, int unset)
 +{
 +      static int label_count = 0;
 +      const char **names = (const char **)opt->value;
 +
 +      if (label_count >= 3)
 +              return error("too many labels on the command line");
 +      names[label_count++] = arg;
 +      return 0;
 +}
 +
 +int cmd_merge_file(int argc, const char **argv, const char *prefix)
 +{
 +      const char *names[3] = { NULL, NULL, NULL };
 +      mmfile_t mmfs[3];
 +      mmbuffer_t result = {NULL, 0};
 +      xmparam_t xmp = {{XDF_NEED_MINIMAL}};
 +      int ret = 0, i = 0, to_stdout = 0;
- 
++      int quiet = 0;
 +      int nongit;
-               OPT_SET_INT(0, "diff3", &style, "use a diff3 based merge", XDL_MERGE_DIFF3),
-               OPT_SET_INT(0, "ours", &favor, "for conflicts, use our version",
 +      struct option options[] = {
 +              OPT_BOOLEAN('p', "stdout", &to_stdout, "send results to standard output"),
-               OPT_SET_INT(0, "theirs", &favor, "for conflicts, use their version",
++              OPT_SET_INT(0, "diff3", &xmp.style, "use a diff3 based merge", XDL_MERGE_DIFF3),
++              OPT_SET_INT(0, "ours", &xmp.favor, "for conflicts, use our version",
 +                          XDL_MERGE_FAVOR_OURS),
-                       style = git_xmerge_style;
++              OPT_SET_INT(0, "theirs", &xmp.favor, "for conflicts, use their version",
 +                          XDL_MERGE_FAVOR_THEIRS),
++              OPT_SET_INT(0, "union", &xmp.favor, "for conflicts, use a union version",
++                          XDL_MERGE_FAVOR_UNION),
++              OPT_INTEGER(0, "marker-size", &xmp.marker_size,
++                          "for conflicts, use this marker size"),
 +              OPT__QUIET(&quiet),
 +              OPT_CALLBACK('L', NULL, names, "name",
 +                           "set labels for file1/orig_file/file2", &label_cb),
 +              OPT_END(),
 +      };
 +
++      xmp.level = XDL_MERGE_ZEALOUS_ALNUM;
++      xmp.style = 0;
++      xmp.favor = 0;
++
 +      prefix = setup_git_directory_gently(&nongit);
 +      if (!nongit) {
 +              /* Read the configuration file */
 +              git_config(git_xmerge_config, NULL);
 +              if (0 <= git_xmerge_style)
-                       &xmp, XDL_MERGE_FLAGS(level, style, favor), &result);
++                      xmp.style = git_xmerge_style;
 +      }
 +
 +      argc = parse_options(argc, argv, prefix, options, merge_file_usage, 0);
 +      if (argc != 3)
 +              usage_with_options(merge_file_usage, options);
 +      if (quiet) {
 +              if (!freopen("/dev/null", "w", stderr))
 +                      return error("failed to redirect stderr to /dev/null: "
 +                                   "%s\n", strerror(errno));
 +      }
 +
 +      for (i = 0; i < 3; i++) {
 +              if (!names[i])
 +                      names[i] = argv[i];
 +              if (read_mmfile(mmfs + i, argv[i]))
 +                      return -1;
 +              if (buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
 +                      return error("Cannot merge binary files: %s\n",
 +                                      argv[i]);
 +      }
 +
 +      ret = xdl_merge(mmfs + 1, mmfs + 0, names[0], mmfs + 2, names[2],
++                      &xmp, &result);
 +
 +      for (i = 0; i < 3; i++)
 +              free(mmfs[i].ptr);
 +
 +      if (ret >= 0) {
 +              const char *filename = argv[0];
 +              FILE *f = to_stdout ? stdout : fopen(filename, "wb");
 +
 +              if (!f)
 +                      ret = error("Could not open %s for writing", filename);
 +              else if (result.size &&
 +                       fwrite(result.ptr, result.size, 1, f) != 1)
 +                      ret = error("Could not write to %s", filename);
 +              else if (fclose(f))
 +                      ret = error("Could not close %s", filename);
 +              free(result.ptr);
 +      }
 +
 +      return ret;
 +}

diff --cc t/t6023-merge-file.sh
Simple merge