KT-193: Guard primary constructor modifier list with a lookahead for LPAR

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

@@ -419,13 +419,27 @@ public class JetParsing extends AbstractJetParsing {
         expect(IDENTIFIER, "Class name expected", CLASS_NAME_RECOVERY_SET);
         boolean typeParametersDeclared = parseTypeParameterList(TYPE_PARAMETER_GT_RECOVERY_SET);
 
-        if (parseModifierList(PRIMARY_CONSTRUCTOR_MODIFIER_LIST, false)) {
+        PsiBuilder.Marker beforeConstructorModifiers = mark();
+        boolean hasConstructorModifiers = parseModifierList(PRIMARY_CONSTRUCTOR_MODIFIER_LIST, false);
+
+        // Some modifiers found, but no parentheses following: class has already ended, and we are looking at something else
+        if (hasConstructorModifiers && !atSet(LPAR, LBRACE, COLON) ) {
+            beforeConstructorModifiers.rollbackTo();
+            return CLASS;
+        }
+
+        // We are still inside a class declaration
+        beforeConstructorModifiers.drop();
+
+        if (at(LPAR)) {
             parseValueParameterList(false, TokenSet.create(COLON, LBRACE));
         }
-        else {
+        else if (hasConstructorModifiers) {
-            if (at(LPAR)) {
+            // A comprehensive error message for cases like:
-                parseValueParameterList(false, TokenSet.create(COLON, LBRACE));
+            //    class A private : Foo
-            }
+            // or
+            //    class A private {
+            error("Expecting primary constructor parameter list");
         }
 
         if (at(COLON)) {

compiler/testData/psi/PrimaryConstructorModifiers_ERR.jet

@@ -0,0 +1,13 @@
+open class A
+
+open class AB private {
+    fun foo() {}
+}
+
+class A1 {
+
+}
+
+open class B<T : A> private () {
+
+}

compiler/testData/psi/PrimaryConstructorModifiers_ERR.txt

@@ -0,0 +1,87 @@
+JetFile: PrimaryConstructorModifiers_ERR.jet
+  NAMESPACE
+    CLASS
+      MODIFIER_LIST
+        PsiElement(open)('open')
+      PsiWhiteSpace(' ')
+      PsiElement(class)('class')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('A')
+      PsiWhiteSpace('\n\n')
+      TYPE_PARAMETER_LIST
+        <empty list>
+    CLASS
+      MODIFIER_LIST
+        PsiElement(open)('open')
+      PsiWhiteSpace(' ')
+      PsiElement(class)('class')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('AB')
+      PsiWhiteSpace(' ')
+      TYPE_PARAMETER_LIST
+        <empty list>
+      PRIMARY_CONSTRUCTOR_MODIFIER_LIST
+        PsiElement(private)('private')
+      PsiErrorElement:Expecting primary constructor parameter list
+        <empty list>
+      PsiWhiteSpace(' ')
+      CLASS_BODY
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n    ')
+        FUN
+          PsiElement(fun)('fun')
+          PsiWhiteSpace(' ')
+          PsiElement(IDENTIFIER)('foo')
+          VALUE_PARAMETER_LIST
+            PsiElement(LPAR)('(')
+            PsiElement(RPAR)(')')
+          PsiWhiteSpace(' ')
+          BLOCK
+            PsiElement(LBRACE)('{')
+            PsiElement(RBRACE)('}')
+        PsiWhiteSpace('\n')
+        PsiElement(RBRACE)('}')
+    PsiWhiteSpace('\n\n')
+    CLASS
+      PsiElement(class)('class')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('A1')
+      PsiWhiteSpace(' ')
+      TYPE_PARAMETER_LIST
+        <empty list>
+      CLASS_BODY
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n\n')
+        PsiElement(RBRACE)('}')
+    PsiWhiteSpace('\n\n')
+    CLASS
+      MODIFIER_LIST
+        PsiElement(open)('open')
+      PsiWhiteSpace(' ')
+      PsiElement(class)('class')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('B')
+      TYPE_PARAMETER_LIST
+        PsiElement(LT)('<')
+        TYPE_PARAMETER
+          PsiElement(IDENTIFIER)('T')
+          PsiWhiteSpace(' ')
+          PsiElement(COLON)(':')
+          PsiWhiteSpace(' ')
+          TYPE_REFERENCE
+            USER_TYPE
+              REFERENCE_EXPRESSION
+                PsiElement(IDENTIFIER)('A')
+        PsiElement(GT)('>')
+      PsiWhiteSpace(' ')
+      PRIMARY_CONSTRUCTOR_MODIFIER_LIST
+        PsiElement(private)('private')
+      PsiWhiteSpace(' ')
+      VALUE_PARAMETER_LIST
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace(' ')
+      CLASS_BODY
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n\n')
+        PsiElement(RBRACE)('}')