git diff HEAD...origin/support-multi-byte-char

patch.diff

diff --git a/diff/parse.go b/diff/parse.go
index ab481d0..12b54e8 100644
--- a/diff/parse.go
+++ b/diff/parse.go
@@ -136,9 +136,75 @@ func parseFileHeader(line string) (filename, timestamp string) {
 	ss := line[len(tokenOldFile)+1:]
 	tabi := strings.LastIndex(ss, "\t")
 	if tabi == -1 {
-		return ss, ""
+		return unescapeCString(ss), ""
 	}
-	return ss[:tabi], ss[tabi+1:]
+	return unescapeCString(ss[:tabi]), ss[tabi+1:]
+}
+
+func unescapeCString(str string) string {
+	if !strings.HasPrefix(str, `"`) {
+		// no need to unescape
+		return str
+	}
+	str = strings.TrimPrefix(strings.TrimSuffix(str, `"`), `"`)
+
+	res := make([]byte, 0, len(str))
+	r := strings.NewReader(str)
+LOOP:
+	for {
+		ch, err := r.ReadByte()
+		if err != nil {
+			break
+		}
+		if ch != '\\' {
+			res = append(res, ch)
+			continue
+		}
+
+		ch, err = r.ReadByte()
+		if err != nil {
+			break
+		}
+		switch ch {
+		case 'a':
+			res = append(res, '\a')
+		case 'b':
+			res = append(res, '\b')
+		case 't':
+			res = append(res, '\t')
+		case 'n':
+			res = append(res, '\n')
+		case 'v':
+			res = append(res, '\v')
+		case 'f':
+			res = append(res, '\f')
+		case 'r':
+			res = append(res, '\r')
+		case '"':
+			res = append(res, '"')
+		case '\\':
+			res = append(res, '\\')
+		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			if err := r.UnreadByte(); err != nil {
+				break LOOP
+			}
+			var oct [3]byte
+			if n, _ := r.Read(oct[:]); n < 3 {
+				res = append(res, oct[:n]...)
+				break LOOP
+			}
+			ch, err := strconv.ParseUint(string(oct[:]), 8, 8)
+			if err != nil {
+				res = append(res, oct[:]...)
+				break
+			}
+			res = append(res, byte(ch))
+		default:
+			res = append(res, ch)
+		}
+	}
+
+	return string(res)
 }
 
 func parseExtendedHeader(r *bufio.Reader) []string {
diff --git "a/diff/testdata/\"日本語\".diff" "b/diff/testdata/\"日本語\".diff"
new file mode 100644
index 0000000..08f812a
--- /dev/null
+++ "b/diff/testdata/\"日本語\".diff"
@@ -0,0 +1,10 @@
+diff --git "a/\"\346\227\245\346\234\254\350\252\236\".old.txt" "b/\"\346\227\245\346\234\254\350\252\236\".new.txt"
+index 5f5a9e4..feeb01f 100644
+--- "a/\"\346\227\245\346\234\254\350\252\236\".old.txt"
++++ "b/\"\346\227\245\346\234\254\350\252\236\".new.txt"
+@@ -1,3 +1,4 @@
+ 変更なし
+-行削除
++行追加
++行追加
+ 変更なし
diff --git "a/diff/testdata/\"日本語\".diff.json" "b/diff/testdata/\"日本語\".diff.json"
new file mode 100644
index 0000000..51c6b9c
--- /dev/null
+++ "b/diff/testdata/\"日本語\".diff.json"
@@ -0,0 +1,58 @@
+[
+  {
+    "PathOld": "a/\"日本語\".old.txt",
+    "PathNew": "b/\"日本語\".new.txt",
+    "TimeOld": "",
+    "TimeNew": "",
+    "Hunks": [
+      {
+        "StartLineOld": 1,
+        "LineLengthOld": 3,
+        "StartLineNew": 1,
+        "LineLengthNew": 4,
+        "Section": "",
+        "Lines": [
+          {
+            "Type": 0,
+            "Content": "変更なし",
+            "LnumDiff": 1,
+            "LnumOld": 1,
+            "LnumNew": 1
+          },
+          {
+            "Type": 2,
+            "Content": "行削除",
+            "LnumDiff": 2,
+            "LnumOld": 2,
+            "LnumNew": 0
+          },
+          {
+            "Type": 1,
+            "Content": "行追加",
+            "LnumDiff": 3,
+            "LnumOld": 0,
+            "LnumNew": 2
+          },
+          {
+            "Type": 1,
+            "Content": "行追加",
+            "LnumDiff": 4,
+            "LnumOld": 0,
+            "LnumNew": 3
+          },
+          {
+            "Type": 0,
+            "Content": "変更なし",
+            "LnumDiff": 5,
+            "LnumOld": 3,
+            "LnumNew": 4
+          }
+        ]
+      }
+    ],
+    "Extended": [
+      "diff --git \"a/\\\"\\346\\227\\245\\346\\234\\254\\350\\252\\236\\\".old.txt\" \"b/\\\"\\346\\227\\245\\346\\234\\254\\350\\252\\236\\\".new.txt\"",
+      "index 5f5a9e4..feeb01f 100644"
+    ]
+  }
+]
diff --git "a/diff/testdata/\"日本語\".new.txt" "b/diff/testdata/\"日本語\".new.txt"
new file mode 100644
index 0000000..feeb01f
--- /dev/null
+++ "b/diff/testdata/\"日本語\".new.txt"
@@ -0,0 +1,4 @@
+変更なし
+行追加
+行追加
+変更なし
diff --git "a/diff/testdata/\"日本語\".old.txt" "b/diff/testdata/\"日本語\".old.txt"
new file mode 100644
index 0000000..5f5a9e4
--- /dev/null
+++ "b/diff/testdata/\"日本語\".old.txt"
@@ -0,0 +1,3 @@
+変更なし
+行削除
+変更なし
diff --git a/diff/testdata/gen.sh b/diff/testdata/gen.sh
index 048fd60..65f089c 100644
--- a/diff/testdata/gen.sh
+++ b/diff/testdata/gen.sh
@@ -11,3 +11,4 @@ git diff --no-index /dev/null "empty space.txt" > empty_space.diff
 git diff --no-index golint.{old,new}.go > golint.diff
 git diff --no-index empty.txt /dev/null > newline_and_empty_deleted.diff
 git diff --no-index golint.{old,new}.go >> newline_and_empty_deleted.diff
+git diff --no-index \"日本語\".{old,new}.txt >> \"日本語\".diff