Improve parser recovery for list of value parameters/arguments

compiler/frontend/src/org/jetbrains/jet/lang/parsing/JetParsing.java

@@ -50,6 +50,7 @@ public class JetParsing extends AbstractJetParsing {
     private static final TokenSet IMPORT_RECOVERY_SET = TokenSet.create(AS_KEYWORD, DOT, EOL_OR_SEMICOLON);
     /*package*/ static final TokenSet TYPE_REF_FIRST = TokenSet.create(LBRACKET, IDENTIFIER, FUN_KEYWORD, LPAR, CAPITALIZED_THIS_KEYWORD, HASH);
     private static final TokenSet RECEIVER_TYPE_TERMINATORS = TokenSet.create(DOT, SAFE_ACCESS);
+    private static final TokenSet VALUE_PARAMETER_FIRST = TokenSet.orSet(TokenSet.create(IDENTIFIER, LBRACKET), MODIFIER_KEYWORDS);
 
     static JetParsing createForTopLevel(SemanticWhitespaceAwarePsiBuilder builder) {
         JetParsing jetParsing = new JetParsing(builder);
@@ -1722,9 +1723,11 @@ public class JetParsing extends AbstractJetParsing {
                     else {
                         parseValueParameter();
                     }
-                    if (!at(COMMA)) break;
+                    if (at(COMMA)) {
                         advance(); // COMMA
                     }
+                    else if (!atSet(VALUE_PARAMETER_FIRST)) break;
+                }
             }
         }
 

compiler/testData/psi/recovery/MissingCommaInValueArgumentList.kt

@@ -0,0 +1,5 @@
+val x = foo(
+    a,
+    b
+    c
+)

compiler/testData/psi/recovery/MissingCommaInValueArgumentList.txt

@@ -0,0 +1,32 @@
+JetFile: MissingCommaInValueArgumentList.kt
+  NAMESPACE_HEADER
+    <empty list>
+  PROPERTY
+    PsiElement(val)('val')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('x')
+    PsiWhiteSpace(' ')
+    PsiElement(EQ)('=')
+    PsiWhiteSpace(' ')
+    CALL_EXPRESSION
+      REFERENCE_EXPRESSION
+        PsiElement(IDENTIFIER)('foo')
+      VALUE_ARGUMENT_LIST
+        PsiElement(LPAR)('(')
+        PsiWhiteSpace('\n    ')
+        VALUE_ARGUMENT
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('a')
+        PsiElement(COMMA)(',')
+        PsiWhiteSpace('\n    ')
+        VALUE_ARGUMENT
+          BINARY_EXPRESSION
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('b')
+            PsiWhiteSpace('\n    ')
+            OPERATION_REFERENCE
+              PsiElement(IDENTIFIER)('c')
+            PsiErrorElement:Expecting an element
+              <empty list>
+        PsiWhiteSpace('\n')
+        PsiElement(RPAR)(')')

compiler/testData/psi/recovery/MissingCommaInValueParameterList.kt

@@ -0,0 +1,7 @@
+fun foo(
+    a: Any,
+    b: Int
+    c: String
+) {
+
+}

compiler/testData/psi/recovery/MissingCommaInValueParameterList.txt

@@ -0,0 +1,44 @@
+JetFile: MissingCommaInValueParameterList.kt
+  NAMESPACE_HEADER
+    <empty list>
+  FUN
+    PsiElement(fun)('fun')
+    PsiWhiteSpace(' ')
+    PsiElement(IDENTIFIER)('foo')
+    VALUE_PARAMETER_LIST
+      PsiElement(LPAR)('(')
+      PsiWhiteSpace('\n    ')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('a')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('Any')
+      PsiElement(COMMA)(',')
+      PsiWhiteSpace('\n    ')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('b')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('Int')
+      PsiWhiteSpace('\n    ')
+      VALUE_PARAMETER
+        PsiElement(IDENTIFIER)('c')
+        PsiElement(COLON)(':')
+        PsiWhiteSpace(' ')
+        TYPE_REFERENCE
+          USER_TYPE
+            REFERENCE_EXPRESSION
+              PsiElement(IDENTIFIER)('String')
+      PsiWhiteSpace('\n')
+      PsiElement(RPAR)(')')
+    PsiWhiteSpace(' ')
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n\n')
+      PsiElement(RBRACE)('}')