1 files changed, 106 insertions, 0 deletions
diff --git a/builtin/merge-file.c b/builtin/merge-file.c
new file mode 100644
index 0000000000..6c4afb5a38
--- /dev/null
+++ b/builtin/merge-file.c
@@ -0,0 +1,106 @@
+#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 = {{0}};
+	int ret = 0, i = 0, to_stdout = 0;
+	int quiet = 0;
+	int prefixlen = 0;
+	struct option options[] = {
+		OPT_BOOLEAN('p', "stdout", &to_stdout, "send results to standard output"),
+		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),
+		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;
+
+	if (startup_info->have_repository) {
+		/* Read the configuration file */
+		git_config(git_xmerge_config, NULL);
+		if (0 <= git_xmerge_style)
+			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));
+	}
+
+	if (prefix)
+		prefixlen = strlen(prefix);
+
+	for (i = 0; i < 3; i++) {
+		const char *fname = prefix_filename(prefix, prefixlen, argv[i]);
+		if (!names[i])
+			names[i] = argv[i];
+		if (read_mmfile(mmfs + i, fname))
+			return -1;
+		if (buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
+			return error("Cannot merge binary files: %s\n",
+					argv[i]);
+	}
+
+	xmp.ancestor = names[1];
+	xmp.file1 = names[0];
+	xmp.file2 = names[2];
+	ret = xdl_merge(mmfs + 1, mmfs + 0, mmfs + 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;
+}