Added --branch-log to option to fast-import.

This option can be used to have a record of every commit, the mark
(if supplied) and branch name of the commit recorded into a log file
when the commit is generated.  This log can be useful to verify the
results of an import as the commits can be compared to some source
repository matching commits through the mark value.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

fast-import.c

@@ -248,6 +248,7 @@ static struct tag *last_tag;
 /* Input stream parsing */
 static struct strbuf command_buf;
 static unsigned long next_mark;
+static FILE* branch_log;
 
 
 static void alloc_objects(int cnt)
@@ -1137,7 +1138,7 @@ static void dump_marks_helper(FILE *f,
 	} else {
 		for (k = 0; k < 1024; k++) {
 			if (m->data.marked[k])
-				fprintf(f, "%lu,%s\n", base + k,
+				fprintf(f, ":%lu %s\n", base + k,
 					sha1_to_hex(m->data.marked[k]->sha1));
 		}
 	}
@@ -1476,6 +1477,18 @@ static void cmd_new_commit()
 	store_object(OBJ_COMMIT, body, sp - body, NULL, b->sha1, next_mark);
 	free(body);
 	b->last_commit = object_count_by_type[OBJ_COMMIT];
+
+	if (branch_log) {
+		int need_dq = quote_c_style(b->name, NULL, NULL, 0);
+		fprintf(branch_log, "commit ");
+		if (need_dq) {
+			fputc('"', branch_log);
+			quote_c_style(b->name, NULL, branch_log, 0);
+			fputc('"', branch_log);
+		} else
+			fprintf(branch_log, "%s", b->name);
+		fprintf(branch_log," :%lu %s\n",next_mark,sha1_to_hex(b->sha1));
+	}
 }
 
 static void cmd_new_tag()
@@ -1490,6 +1503,7 @@ static void cmd_new_tag()
 	size_t msglen;
 	char *body;
 	struct tag *t;
+	unsigned long from_mark = 0;
 	unsigned char sha1[20];
 
 	/* Obtain the new tag name from the rest of our command */
@@ -1528,10 +1542,10 @@ static void cmd_new_tag()
 	if (s) {
 		memcpy(sha1, s->sha1, 20);
 	} else if (*from == ':') {
-		unsigned long idnum = strtoul(from + 1, NULL, 10);
-		struct object_entry *oe = find_mark(idnum);
+		from_mark = strtoul(from + 1, NULL, 10);
+		struct object_entry *oe = find_mark(from_mark);
 		if (oe->type != OBJ_COMMIT)
-			die("Mark :%lu not a commit", idnum);
+			die("Mark :%lu not a commit", from_mark);
 		memcpy(sha1, oe->sha1, 20);
 	} else if (!get_sha1(from, sha1)) {
 		unsigned long size;
@@ -1572,10 +1586,22 @@ static void cmd_new_tag()
 
 	store_object(OBJ_TAG, body, sp - body, NULL, t->sha1, 0);
 	free(body);
+
+	if (branch_log) {
+		int need_dq = quote_c_style(t->name, NULL, NULL, 0);
+		fprintf(branch_log, "tag ");
+		if (need_dq) {
+			fputc('"', branch_log);
+			quote_c_style(t->name, NULL, branch_log, 0);
+			fputc('"', branch_log);
+		} else
+			fprintf(branch_log, "%s", t->name);
+		fprintf(branch_log," :%lu %s\n",from_mark,sha1_to_hex(t->sha1));
+	}
 }
 
 static const char fast_import_usage[] =
-"git-fast-import [--objects=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file] temp.pack";
+"git-fast-import [--objects=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file] [--branch-log=log] temp.pack";
 
 int main(int argc, const char **argv)
 {
@@ -1602,6 +1628,11 @@ int main(int argc, const char **argv)
 			max_active_branches = strtoul(a + 18, NULL, 0);
 		else if (!strncmp(a, "--export-marks=", 15))
 			mark_file = a + 15;
+		else if (!strncmp(a, "--branch-log=", 13)) {
+			branch_log = fopen(a + 13, "w");
+			if (!branch_log)
+				die("Can't create %s: %s", a + 13, strerror(errno));
+		}
 		else
 			die("unknown option %s", a);
 	}
@@ -1647,6 +1678,7 @@ int main(int argc, const char **argv)
 	dump_branches();
 	dump_tags();
 	dump_marks();
+	fclose(branch_log);
 
 	fprintf(stderr, "%s statistics:\n", argv[0]);
 	fprintf(stderr, "---------------------------------------------------\n");