From dba64fbcea659443c0fd085e7bde7e397a9d323a Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Tue, 28 Jun 2011 17:56:01 +0200
Subject: [PATCH] a trailing comma in argument list is not an error (PY-4016)

---
 .../python/parsing/FunctionParsing.java          |  3 +++
 python/testData/psi/TrailingCommaInArgList.py    |  2 ++
 python/testData/psi/TrailingCommaInArgList.txt   | 16 ++++++++++++++++
 .../com/jetbrains/python/PythonParsingTest.java  |  4 ++++
 4 files changed, 25 insertions(+)
 create mode 100644 python/testData/psi/TrailingCommaInArgList.py
 create mode 100644 python/testData/psi/TrailingCommaInArgList.txt

diff --git a/python/src/com/jetbrains/python/parsing/FunctionParsing.java b/python/src/com/jetbrains/python/parsing/FunctionParsing.java
index a91532380914..70c2bb67bbab 100644
--- a/python/src/com/jetbrains/python/parsing/FunctionParsing.java
+++ b/python/src/com/jetbrains/python/parsing/FunctionParsing.java
@@ -157,6 +157,9 @@ public class FunctionParsing extends Parsing {
       }
       else {
         parameter.rollbackTo();
+        if (atToken(endToken)) {
+          break;
+        }
         PsiBuilder.Marker invalidElements = myBuilder.mark();
         while (!atToken(endToken) && !atToken(PyTokenTypes.LINE_BREAK) && !atToken(PyTokenTypes.COMMA) && !atToken(null)) {
           nextToken();
diff --git a/python/testData/psi/TrailingCommaInArgList.py b/python/testData/psi/TrailingCommaInArgList.py
new file mode 100644
index 000000000000..9abd27d64348
--- /dev/null
+++ b/python/testData/psi/TrailingCommaInArgList.py
@@ -0,0 +1,2 @@
+def some_function(a,):
+    pass
\ No newline at end of file
diff --git a/python/testData/psi/TrailingCommaInArgList.txt b/python/testData/psi/TrailingCommaInArgList.txt
new file mode 100644
index 000000000000..5d107c77c9b2
--- /dev/null
+++ b/python/testData/psi/TrailingCommaInArgList.txt
@@ -0,0 +1,16 @@
+PyFile:TrailingCommaInArgList.py
+  PyFunction('some_function')
+    PsiElement(Py:DEF_KEYWORD)('def')
+    PsiWhiteSpace(' ')
+    PsiElement(Py:IDENTIFIER)('some_function')
+    PyParameterList
+      PsiElement(Py:LPAR)('(')
+      PyNamedParameter('a')
+        PsiElement(Py:IDENTIFIER)('a')
+      PsiElement(Py:COMMA)(',')
+      PsiElement(Py:RPAR)(')')
+    PsiElement(Py:COLON)(':')
+    PsiWhiteSpace('\n    ')
+    PyStatementList
+      PyPassStatement
+        PsiElement(Py:PASS_KEYWORD)('pass')
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/PythonParsingTest.java b/python/testSrc/com/jetbrains/python/PythonParsingTest.java
index 65fd7b5ed108..75115b2d16a0 100644
--- a/python/testSrc/com/jetbrains/python/PythonParsingTest.java
+++ b/python/testSrc/com/jetbrains/python/PythonParsingTest.java
@@ -271,6 +271,10 @@ public class PythonParsingTest extends ParsingTestCase {
     doTest();
   }
 
+  public void testTrailingCommaInArgList() {  // PY-4016
+    doTest();
+  }
+
   public void doTest() {
     doTest(LanguageLevel.PYTHON25);
   }