Auto merge of #18394 - jdm:filtererr, r=xidorn

Report more specific error for invalid filter properties

Reviewed by xidorn in https://bugzilla.mozilla.org/show_bug.cgi?id=1386900.

---
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix [bug 1386900](https://bugzilla.mozilla.org/show_bug.cgi?id=1386900).
- [X] There are tests for these changes

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---
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components/style/values/specified/effects.rs

@@ -4,9 +4,9 @@
 
 //! Specified types for CSS values related to effects.
 
-use cssparser::Parser;
+use cssparser::{Parser, Token, BasicParseError};
 use parser::{Parse, ParserContext};
-use style_traits::{ParseError, StyleParseError};
+use style_traits::{ParseError, StyleParseError, ValueParseError};
 #[cfg(not(feature = "gecko"))]
 use values::Impossible;
 use values::computed::{Context, NonNegativeNumber as ComputedNonNegativeNumber, ToComputedValue};
@@ -161,9 +161,14 @@ impl Parse for Filter {
                 return Ok(GenericFilter::Url(url));
             }
         }
-        let function = input.expect_function()?.clone();
+        let function = match input.expect_function() {
+            Ok(f) => f.clone(),
+            Err(BasicParseError::UnexpectedToken(t)) =>
+                return Err(ValueParseError::InvalidFilter(t.clone()).into()),
+            Err(e) => return Err(e.into()),
+        };
         input.parse_nested_block(|i| {
-            try_match_ident_ignore_ascii_case! { function,
+            match_ignore_ascii_case! { &*function,
                 "blur" => Ok(GenericFilter::Blur((Length::parse_non_negative(context, i)?).into())),
                 "brightness" => Ok(GenericFilter::Brightness(Factor::parse(context, i)?)),
                 "contrast" => Ok(GenericFilter::Contrast(Factor::parse(context, i)?)),
@@ -174,6 +179,7 @@ impl Parse for Filter {
                 "saturate" => Ok(GenericFilter::Saturate(Factor::parse(context, i)?)),
                 "sepia" => Ok(GenericFilter::Sepia(Factor::parse(context, i)?)),
                 "drop-shadow" => Ok(GenericFilter::DropShadow(Parse::parse(context, i)?)),
+                _ => Err(ValueParseError::InvalidFilter(Token::Function(function.clone())).into()),
             }
         })
     }

components/style_traits/lib.rs

@@ -132,6 +132,14 @@ pub enum StyleParseError<'i> {
 pub enum ValueParseError<'i> {
     /// An invalid token was encountered while parsing a color value.
     InvalidColor(Token<'i>),
+    /// An invalid filter value was encountered.
+    InvalidFilter(Token<'i>),
+}
+
+impl<'a> From<ValueParseError<'a>> for ParseError<'a> {
+    fn from(this: ValueParseError<'a>) -> Self {
+        StyleParseError::ValueError(this).into()
+    }
 }
 
 impl<'i> ValueParseError<'i> {

ports/geckolib/error_reporter.rs

@@ -122,7 +122,8 @@ fn extract_error_param<'a>(err: ParseError<'a>) -> Option<ErrorString<'a>> {
 
 fn extract_value_error_param<'a>(err: ValueParseError<'a>) -> ErrorString<'a> {
     match err {
-        ValueParseError::InvalidColor(t) => ErrorString::UnexpectedToken(t),
+        ValueParseError::InvalidColor(t) |
+        ValueParseError::InvalidFilter(t) => ErrorString::UnexpectedToken(t),
     }
 }
 
@@ -221,6 +222,7 @@ impl<'a> ErrorHelpers<'a> for ContextualParseError<'a> {
                         PropertyDeclarationParseError::InvalidValue(_, ref err))))) => {
                 let prefix = match *err {
                     Some(ValueParseError::InvalidColor(_)) => Some(&b"PEColorNotColor\0"[..]),
+                    Some(ValueParseError::InvalidFilter(_)) => Some(&b"PEExpectedNoneOrURLOrFilterFunction\0"[..]),
                     _ => None,
                 };
                 return (prefix, b"PEValueParsingError\0", Action::Drop);