Don't stop at commas when trying to find the end of a statement.

Author: adampauls

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -249,11 +249,11 @@ object Parsers {
 
     /** Skip on error to next safe point.
      */
-    protected def skip(): Unit =
+    protected def skip(stopAtComma: Boolean): Unit =
       val lastRegion = in.currentRegion
       def atStop =
         in.token == EOF
-        || skipStopTokens.contains(in.token) && (in.currentRegion eq lastRegion)
+        || ((stopAtComma && in.token == COMMA) || skipStopTokens.contains(in.token)) && (in.currentRegion eq lastRegion)
       while !atStop do
         in.nextToken()
       lastErrorOffset = in.offset
@@ -278,7 +278,7 @@ object Parsers {
       if (in.token == EOF) incompleteInputError(msg)
       else
         syntaxError(msg, offset)
-        skip()
+        skip(stopAtComma = true)
 
     /** Consume one token of the specified type, or
       * signal an error if it is not there.
@@ -346,7 +346,7 @@ object Parsers {
             false // it's a statement that might be legal in an outer context
           else
             in.nextToken() // needed to ensure progress; otherwise we might cycle forever
-            skip()
+            skip(stopAtComma=false)
             true
 
       in.observeOutdented()

compiler/src/dotty/tools/dotc/parsing/Tokens.scala

@@ -285,7 +285,7 @@ object Tokens extends TokensCommon {
 
   final val endMarkerTokens = identifierTokens | BitSet(IF, WHILE, FOR, MATCH, TRY, NEW, THROW, GIVEN, VAL, THIS)
 
-  final val skipStopTokens = BitSet(SEMI, NEWLINE, NEWLINES, RBRACE, RPAREN, RBRACKET, OUTDENT, COMMA)
+  final val skipStopTokens = BitSet(SEMI, NEWLINE, NEWLINES, RBRACE, RPAREN, RBRACKET, OUTDENT)
 
   final val softModifierNames = Set(nme.inline, nme.opaque, nme.open, nme.transparent, nme.infix)
 }