1 files changed, 14 insertions, 9 deletions
diff --git a/devtools/server/actors/style-rule.js b/devtools/server/actors/style-rule.js
index 9ddd6a380c..2be6e981ea 100644
--- a/devtools/server/actors/style-rule.js
+++ b/devtools/server/actors/style-rule.js
@@ -9,7 +9,9 @@ const {
   styleRuleSpec,
 } = require("resource://devtools/shared/specs/style-rule.js");
 
-const { getCSSLexer } = require("resource://devtools/shared/css/lexer.js");
+const {
+  InspectorCSSParserWrapper,
+} = require("resource://devtools/shared/css/lexer.js");
 const TrackChangeEmitter = require("resource://devtools/server/actors/utils/track-change-emitter.js");
 const {
   getRuleText,
@@ -502,6 +504,12 @@ class StyleRuleActor extends Actor {
     // Flag that will be set to true if the rule has a non-at-rule parent rule
     let computeDesugaredSelector = false;
 
+    // We don't want to compute ancestor rules for keyframe rule, as they can only be
+    // in @keyframes rules.
+    if (this.ruleClassName === "CSSKeyframeRule") {
+      return { ancestorData, computeDesugaredSelector };
+    }
+
     // Go through all ancestor so we can build an array of all the media queries and
     // layers this rule is in.
     for (const ancestorRule of this.ancestorRules) {
@@ -1316,23 +1324,20 @@ function getSelectorOffsets(initialText, line, column) {
     line,
     column
   );
-  const lexer = getCSSLexer(text);
+  const lexer = new InspectorCSSParserWrapper(text);
 
   // Search forward for the opening brace.
   let endOffset;
-  while (true) {
-    const token = lexer.nextToken();
-    if (!token) {
-      break;
-    }
-    if (token.tokenType === "symbol" && token.text === "{") {
+  let token;
+  while ((token = lexer.nextToken())) {
+    if (token.tokenType === "CurlyBracketBlock") {
       if (endOffset === undefined) {
         break;
       }
       return [textOffset, textOffset + endOffset];
     }
     // Preserve comments and whitespace just before the "{".
-    if (token.tokenType !== "comment" && token.tokenType !== "whitespace") {
+    if (token.tokenType !== "Comment" && token.tokenType !== "WhiteSpace") {
       endOffset = token.endOffset;
     }
   }