Handle single-version browser ranges. Closes Compass#1853.

Author: chriseppstein

core/stylesheets/compass/_support.scss

@@ -275,9 +275,9 @@ $css-sel2-support-threshold: $critical-usage-threshold !default;
     $old-range: map-get($ranges, $browser);
     @if $old-range {
       $old-min: nth($old-range, 1);
-      $old-max: nth($old-range, 2);
+      $old-max: if(length($old-range) == 1, $old-min, nth($old-range, 2));
       $new-min: nth($new-range, 1);
-      $new-max: nth($new-range, 2);
+      $new-max: if(length($new-range) == 1, $new-min, nth($new-range, 2));
       $maximin: if(compare-browser-versions($browser, $old-min, $new-min) > 0,
                    $old-min, $new-min);
       $minimax: if(compare-browser-versions($browser, $old-max, $new-max) < 0,

core/test/integrations/projects/compass/css/issue-1853.css

@@ -0,0 +1,10 @@
+.use-case {
+  background-image: url('data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4gPHN2ZyB2ZXJzaW9uPSIxLjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+PGRlZnM+PGxpbmVhckdyYWRpZW50IGlkPSJncmFkIiBncmFkaWVudFVuaXRzPSJvYmplY3RCb3VuZGluZ0JveCIgeDE9IjAuNSIgeTE9IjAuMCIgeDI9IjAuNSIgeTI9IjEuMCI+PHN0b3Agb2Zmc2V0PSIwJSIgc3RvcC1jb2xvcj0iI2ZmMDAwMCIvPjxzdG9wIG9mZnNldD0iMTAwJSIgc3RvcC1jb2xvcj0iIzAwMDBmZiIvPjwvbGluZWFyR3JhZGllbnQ+PC9kZWZzPjxyZWN0IHg9IjAiIHk9IjAiIHdpZHRoPSIxMDAlIiBoZWlnaHQ9IjEwMCUiIGZpbGw9InVybCgjZ3JhZCkiIC8+PC9zdmc+IA==');
+  background-size: 100%;
+  background-image: -webkit-gradient(linear, 50% 0%, 50% 100%, color-stop(0%, #ff0000), color-stop(100%, #0000ff));
+  background-image: -moz-linear-gradient(#ff0000, #0000ff);
+  background-image: -webkit-linear-gradient(#ff0000, #0000ff);
+  background-image: linear-gradient(#ff0000, #0000ff); }
+
+.simple {
+  content: (ie: "9" "9"); }

core/test/integrations/projects/compass/sass/issue-1853.scss

@@ -0,0 +1,16 @@
+@import "compass/support";
+@import "compass/css3/images";
+
+// An actual use-case that demonstrates the problem
+.use-case {
+  @include with-browser-ranges(css-mediaqueries) {
+    @include background-image(linear-gradient(red, blue));
+  }
+}
+
+// A simplification of the issue
+$ranges: (ie: "9" "11");
+$new-ranges: (ie: "9");
+.simple {
+  content: inspect(intersect-browser-ranges($ranges, $new-ranges));
+}