style: Make PercentageOrNumber also reject negative percentages.

servo · Mar 26, 2017 · 3723794 · 3723794
1 parent c2d9f66
commit 3723794
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Showing 2 changed files with 20 additions and 10 deletions.
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
@@ -909,16 +909,27 @@ impl ToCss for Percentage {
     }
 }
 
-impl Parse for Percentage {
-    #[inline]
-    fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
-        let context = AllowedNumericType::All;
+impl Percentage {
+    fn parse_internal(input: &mut Parser, context: AllowedNumericType) -> Result<Self, ()> {
         match try!(input.next()) {
-            Token::Percentage(ref value) if context.is_ok(value.unit_value) =>
-                Ok(Percentage(value.unit_value)),
+            Token::Percentage(ref value) if context.is_ok(value.unit_value) => {
+                Ok(Percentage(value.unit_value))
+            }
             _ => Err(())
         }
     }
+
+    /// Parses a percentage token, but rejects it if it's negative.
+    pub fn parse_non_negative(input: &mut Parser) -> Result<Self, ()> {
+        Self::parse_internal(input, AllowedNumericType::NonNegative)
+    }
+}
+
+impl Parse for Percentage {
+    #[inline]
+    fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
+        Self::parse_internal(input, AllowedNumericType::All)
+    }
 }
 
 impl ComputedValueAsSpecified for Percentage {}

diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
@@ -585,13 +585,12 @@ pub enum NumberOrPercentage {
 no_viewport_percentage!(NumberOrPercentage);
 
 impl Parse for NumberOrPercentage {
-    fn parse(context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
-        if let Ok(per) = input.try(|input| Percentage::parse(context, input)) {
+    fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
+        if let Ok(per) = input.try(Percentage::parse_non_negative) {
             return Ok(NumberOrPercentage::Percentage(per));
         }
 
-        let num = try!(Number::parse_non_negative(input));
-        Ok(NumberOrPercentage::Number(num))
+        Number::parse_non_negative(input).map(NumberOrPercentage::Number)
     }
 }