From ccbb482b08ffa39f830ae876b6e0d455bb6e114d Mon Sep 17 00:00:00 2001
From: Andrey Breslav <abreslav@abreslav-mac.labs.intellij.net>
Date: Wed, 8 Jun 2011 18:49:02 +0400
Subject: [PATCH] Infinite loop in the parser fixed

---
 .../jet/lang/parsing/JetExpressionParsing.java  | 15 ++++++++++-----
 idea/testData/psi/HangOnLonelyModifier.jet      |  3 +++
 idea/testData/psi/HangOnLonelyModifier.txt      | 17 +++++++++++++++++
 idea/testData/psi/When_ERR.txt                  |  2 +-
 4 files changed, 31 insertions(+), 6 deletions(-)
 create mode 100644 idea/testData/psi/HangOnLonelyModifier.jet
 create mode 100644 idea/testData/psi/HangOnLonelyModifier.txt

diff --git a/idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java b/idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java
index 69d6c63cf25..ee7ac511559 100644
--- a/idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java
+++ b/idea/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java
@@ -255,7 +255,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
      */
     public void parseExpression() {
         if (!atSet(EXPRESSION_FIRST)) {
-            error("Expecting an element");
+            error("Expecting an expression");
             return;
         }
         parseBinaryExpression(Precedence.ASSIGNMENT);
@@ -952,17 +952,17 @@ public class JetExpressionParsing extends AbstractJetParsing {
      * modifiers declarationRest
      */
     private boolean parseLocalDeclaration() {
-        PsiBuilder.Marker decls = mark();
+        PsiBuilder.Marker decl = mark();
         JetParsing.TokenDetector enumDetector = new JetParsing.TokenDetector(ENUM_KEYWORD);
         myJetParsing.parseModifierList(MODIFIER_LIST, enumDetector);
 
         JetNodeType declType = parseLocalDeclarationRest(enumDetector.isDetected());
 
         if (declType != null) {
-            decls.done(declType);
+            decl.done(declType);
             return true;
         } else {
-            decls.rollbackTo();
+            decl.rollbackTo();
             return false;
         }
     }
@@ -1129,7 +1129,12 @@ public class JetExpressionParsing extends AbstractJetParsing {
      */
     private void parseStatement() {
         if (!parseLocalDeclaration()) {
-            parseExpression();
+            if (!atSet(EXPRESSION_FIRST)) {
+                errorAndAdvance("Expecting a statement");
+            }
+            else {
+                parseExpression();
+            }
         }
     }
 
diff --git a/idea/testData/psi/HangOnLonelyModifier.jet b/idea/testData/psi/HangOnLonelyModifier.jet
new file mode 100644
index 00000000000..9a141db9f8e
--- /dev/null
+++ b/idea/testData/psi/HangOnLonelyModifier.jet
@@ -0,0 +1,3 @@
+fun test() {
+in
+}
diff --git a/idea/testData/psi/HangOnLonelyModifier.txt b/idea/testData/psi/HangOnLonelyModifier.txt
new file mode 100644
index 00000000000..954cac7d2e8
--- /dev/null
+++ b/idea/testData/psi/HangOnLonelyModifier.txt
@@ -0,0 +1,17 @@
+JetFile: HangOnLonelyModifier.jet
+  NAMESPACE
+    FUN
+      PsiElement(fun)('fun')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('test')
+      VALUE_PARAMETER_LIST
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace(' ')
+      BLOCK
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n')
+        PsiErrorElement:Expecting a statement
+          PsiElement(in)('in')
+        PsiWhiteSpace('\n')
+        PsiElement(RBRACE)('}')
\ No newline at end of file
diff --git a/idea/testData/psi/When_ERR.txt b/idea/testData/psi/When_ERR.txt
index 4f00772aab9..2337bebefe9 100644
--- a/idea/testData/psi/When_ERR.txt
+++ b/idea/testData/psi/When_ERR.txt
@@ -155,7 +155,7 @@ JetFile: When_ERR.jet
                 <empty list>
             PsiWhiteSpace('  ')
             PsiElement(DOUBLE_ARROW)('=>')
-            PsiErrorElement:Expecting an element
+            PsiErrorElement:Expecting an expression
               <empty list>
           PsiWhiteSpace(' ')
           PsiElement(SEMICOLON)(';')