Fix bug with multi-line string literals

src/dfmt/formatter.d

@@ -1398,6 +1398,9 @@ private:
 
     void writeToken()
     {
+        import std.range:retro;
+        import std.algorithm.searching:countUntil;
+
         if (current.text is null)
         {
             immutable s = str(current.type);
@@ -1412,7 +1415,18 @@ private:
                 output.put(current.text.replace("\r", ""));
             else
                 output.put(current.text);
+            switch (current.type)
+            {
+            case tok!"stringLiteral":
+            case tok!"wstringLiteral":
+            case tok!"dstringLiteral":
+                immutable o = current.text.retro().countUntil('\n');
+                currentLineLength += o == -1 ? current.text.length : o;
+                break;
+            default:
                 currentLineLength += current.text.length;
+                break;
+            }
         }
         index++;
     }

tests/allman/multiline_string.d.ref

@@ -0,0 +1,12 @@
+unittest
+{
+    someFunctionCall(`
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	`, paramater);
+}

tests/multiline_string.d

@@ -0,0 +1,13 @@
+unittest
+{
+	someFunctionCall(`
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	`,
+			paramater);
+}

tests/otbs/multiline_string.d.ref

@@ -0,0 +1,11 @@
+unittest {
+    someFunctionCall(`
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	multi-line string
+	`, paramater);
+}