From fbdee15c5358dcda4c087c010747d730202a1a50 Mon Sep 17 00:00:00 2001
From: Kuba Pawlaczyk <pawlaczyk.jakub@gmail.com>
Date: Tue, 28 Mar 2017 21:38:42 +0200
Subject: [PATCH] Fixed #15200 - added missing comma in
 {background,mask}-position serialization

---
 .../style/properties/shorthand/background.mako.rs    |  3 +++
 components/style/properties/shorthand/mask.mako.rs   |  4 ++++
 tests/unit/style/properties/serialization.rs         | 12 ++++++++++--
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/components/style/properties/shorthand/background.mako.rs b/components/style/properties/shorthand/background.mako.rs
index a0747e9ea81..25954c768e6 100644
--- a/components/style/properties/shorthand/background.mako.rs
+++ b/components/style/properties/shorthand/background.mako.rs
@@ -234,6 +234,9 @@
                 self.background_position_x.0[i].to_css(dest)?;
                 dest.write_str(" ")?;
                 self.background_position_y.0[i].to_css(dest)?;
+                if i < len - 1 {
+                    dest.write_str(", ")?;
+                }
             }
             Ok(())
         }
diff --git a/components/style/properties/shorthand/mask.mako.rs b/components/style/properties/shorthand/mask.mako.rs
index 01caeddb9ca..e8229d59800 100644
--- a/components/style/properties/shorthand/mask.mako.rs
+++ b/components/style/properties/shorthand/mask.mako.rs
@@ -226,7 +226,11 @@
 
             for i in 0..len {
                 self.mask_position_x.0[i].to_css(dest)?;
+                dest.write_str(" ")?;
                 self.mask_position_y.0[i].to_css(dest)?;
+                if i < len - 1 {
+                    dest.write_str(", ")?;
+                }
             }
 
             Ok(())
diff --git a/tests/unit/style/properties/serialization.rs b/tests/unit/style/properties/serialization.rs
index 72296d9f98c..592f089651c 100644
--- a/tests/unit/style/properties/serialization.rs
+++ b/tests/unit/style/properties/serialization.rs
@@ -741,14 +741,14 @@ mod shorthand_serialization {
             // https://github.com/servo/servo/issues/15398 )
             // With background, the color is one exception as it should only appear once for
             // multiple backgrounds.
-            // Below, background-position and background-origin only have one value.
+            // Below background-origin only has one value.
             let block_text = "\
                 background-color: rgb(0, 0, 255); \
                 background-image: url(\"http://servo/test.png\"), none; \
                 background-repeat: repeat-x, repeat-y; \
                 background-attachment: scroll, scroll; \
                 background-size: 70px 50px, 20px 30px; \
-                background-position: 7px 4px; \
+                background-position: 7px 4px, 5px 6px; \
                 background-origin: border-box; \
                 background-clip: padding-box, padding-box;";
             let block = parse_declaration_block(block_text);
@@ -905,6 +905,14 @@ mod shorthand_serialization {
                 repeat-x padding-box subtract;"
             );
         }
+
+        #[test]
+        fn serialize_mask_position_with_multiple_values() {
+            let block_text = "mask-position: 1px 2px, 4px 3px;";
+            let block = parse_declaration_block(block_text);
+            let serialization = block.to_css_string();
+            assert_eq!(serialization, block_text);
+        }
     }
 
     mod scroll_snap_type {