Remove whitespace around @import url(...), fixes #296

css/css.go

@@ -185,7 +185,15 @@ func (c *cssMinifier) minifyGrammar() error {
 			if ToHash(data[1:]) == Import && len(values) == 2 && values[1].TokenType == css.URLToken {
 				url := values[1].Data
 				if url[4] != '"' && url[4] != '\'' {
-					url = url[3:]
+					a := 4
+					for parse.IsWhitespace(url[a]) || parse.IsNewline(url[a]) {
+						a++
+					}
+					b := len(url) - 2
+					for parse.IsWhitespace(url[b]) || parse.IsNewline(url[b]) {
+						b--
+					}
+					url = url[a-1 : b+2]
 					url[0] = '"'
 					url[len(url)-1] = '"'
 				} else {

css/css_test.go

@@ -27,6 +27,8 @@ func TestCSS(t *testing.T) {
 		{"@import 'file';", "@import 'file'"},
 		{"@import url('file');", "@import 'file'"},
 		{"@import url(//url);", `@import "//url"`},
+		{"@import url(\n//url\n);", `@import "//url"`},
+		{"@import url();", `@import ""`},
 		{"@font-face { x:y; }", "@font-face{x:y}"},
 
 		{"input[type=\"radio\"]{x:y}", "input[type=radio]{x:y}"},