fast-import: allow for multiple --import-marks= arguments

The --import-marks= option may be specified multiple times on the
commandline and should result in all marks being read in. Only one
import-marks feature may be specified in the stream, which is
overriden by any --import-marks= commandline options.

If one wishes to specify import-marks files in addition to the one
specified in the stream, it is easy to repeat the stream option as a
--import-marks= commandline option.

Also verify this behavior with tests.

Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-fast-import.txt

@@ -867,7 +867,8 @@ it does not.
 The <feature> part of the command may be any string matching
 ^[a-zA-Z][a-zA-Z-]*$ and should be understood by fast-import.
 
-Feature work identical as their option counterparts.
+Feature work identical as their option counterparts with the
+exception of the import-marks feature, see below.
 
 The following features are currently supported:
 
@@ -876,6 +877,11 @@ The following features are currently supported:
 * export-marks
 * force
 
+The import-marks behaves differently from when it is specified as
+commandline option in that only one "feature import-marks" is allowed
+per stream. Also, any --import-marks= specified on the commandline
+will override those from the stream (if any).
+
 `option`
 ~~~~~~~~
 Processes the specified option so that git fast-import behaves in a

fast-import.c

@@ -322,6 +322,7 @@ static struct object_entry *object_table[1 << 16];
 static struct mark_set *marks;
 static const char *export_marks_file;
 static const char *import_marks_file;
+static int import_marks_file_from_stream;
 
 /* Our last blob */
 static struct last_object last_blob = { STRBUF_INIT, 0, 0, 0 };
@@ -2469,9 +2470,19 @@ static void parse_progress(void)
 	skip_optional_lf();
 }
 
-static void option_import_marks(const char *marks)
+static void option_import_marks(const char *marks, int from_stream)
 {
+	if (import_marks_file) {
+		if (from_stream)
+			die("Only one import-marks command allowed per stream");
+
+		/* read previous mark file */
+		if(!import_marks_file_from_stream)
+			read_marks();
+	}
+
 	import_marks_file = xstrdup(marks);
+	import_marks_file_from_stream = from_stream;
 }
 
 static void option_date_format(const char *fmt)
@@ -2538,12 +2549,12 @@ static int parse_one_option(const char *option)
 	return 1;
 }
 
-static int parse_one_feature(const char *feature)
+static int parse_one_feature(const char *feature, int from_stream)
 {
 	if (!prefixcmp(feature, "date-format=")) {
 		option_date_format(feature + 12);
 	} else if (!prefixcmp(feature, "import-marks=")) {
-		option_import_marks(feature + 13);
+		option_import_marks(feature + 13, from_stream);
 	} else if (!prefixcmp(feature, "export-marks=")) {
 		option_export_marks(feature + 13);
 	} else if (!prefixcmp(feature, "force")) {
@@ -2562,7 +2573,7 @@ static void parse_feature(void)
 	if (seen_data_command)
 		die("Got feature command '%s' after data command", feature);
 
-	if (parse_one_feature(feature))
+	if (parse_one_feature(feature, 1))
 		return;
 
 	die("This version of fast-import does not support feature %s.", feature);
@@ -2618,7 +2629,7 @@ static void parse_argv(void)
 		if (parse_one_option(a + 2))
 			continue;
 
-		if (parse_one_feature(a + 2))
+		if (parse_one_feature(a + 2, 0))
 			continue;
 
 		die("unknown option %s", a);

t/t9300-fast-import.sh

@@ -1285,6 +1285,15 @@ test_expect_success 'R: abort on receiving feature after data command' '
 	test_must_fail git fast-import <input
 '
 
+cat >input << EOF
+feature import-marks=git.marks
+feature import-marks=git2.marks
+EOF
+
+test_expect_success 'R: only one import-marks feature allowed per stream' '
+	test_must_fail git fast-import <input
+'
+
 cat >input << EOF
 feature export-marks=git.marks
 blob
@@ -1324,6 +1333,19 @@ test_expect_success \
     'cat input | git fast-import --import-marks=marks.out &&
     test_cmp marks.out marks.new'
 
+
+cat >input <<EOF
+feature import-marks=nonexistant.marks
+feature export-marks=combined.marks
+EOF
+
+test_expect_success 'R: multiple --import-marks= should be honoured' '
+    head -n2 marks.out > one.marks &&
+    tail -n +3 marks.out > two.marks &&
+    git fast-import --import-marks=one.marks --import-marks=two.marks <input &&
+    test_cmp marks.out combined.marks
+'
+
 cat >input << EOF
 option git quiet
 blob