From da88f9caec5b0d0288f15b6036652a388147872a Mon Sep 17 00:00:00 2001
From: Andrey Vlasovskikh <andrey.vlasovskikh@jetbrains.com>
Date: Mon, 18 Feb 2013 13:34:23 +0400
Subject: [PATCH] Fixed augmented assignment inspection for non-commutative
 operations on weak union types (PY-7605)

---
 .../python/inspections/PyAugmentAssignmentInspection.java  | 2 +-
 .../PyAugmentAssignmentInspection/strOrUnknownFirstArg.py  | 7 +++++++
 .../inspections/PyAugmentAssignmentInspectionTest.java     | 5 +++++
 3 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 python/testData/inspections/PyAugmentAssignmentInspection/strOrUnknownFirstArg.py

diff --git a/python/src/com/jetbrains/python/inspections/PyAugmentAssignmentInspection.java b/python/src/com/jetbrains/python/inspections/PyAugmentAssignmentInspection.java
index 5503bae70e43..5762fa6f4b4a 100644
--- a/python/src/com/jetbrains/python/inspections/PyAugmentAssignmentInspection.java
+++ b/python/src/com/jetbrains/python/inspections/PyAugmentAssignmentInspection.java
@@ -74,7 +74,7 @@ public class PyAugmentAssignmentInspection extends PyInspection {
         if ((operations.contains(op) && !changedParts) || (changedParts && commutativeOperations.contains(op))) {
           if (leftExpression instanceof PyReferenceExpression || leftExpression instanceof PySubscriptionExpression) {
             final PyType type = myTypeEvalContext.getType(rightExpression);
-            if (type != null) {
+            if (type != null && !PyTypeChecker.isUnknown(type)) {
               final PyBuiltinCache cache = PyBuiltinCache.getInstance(rightExpression);
               final LanguageLevel languageLevel = LanguageLevel.forElement(rightExpression);
               if (isNumeric(type, cache) || (isString(type, cache, languageLevel) && !changedParts)) {
diff --git a/python/testData/inspections/PyAugmentAssignmentInspection/strOrUnknownFirstArg.py b/python/testData/inspections/PyAugmentAssignmentInspection/strOrUnknownFirstArg.py
new file mode 100644
index 000000000000..f876b7e334f2
--- /dev/null
+++ b/python/testData/inspections/PyAugmentAssignmentInspection/strOrUnknownFirstArg.py
@@ -0,0 +1,7 @@
+def foo(c, x, y):
+    if c:
+        z = x
+    else:
+        z = ''
+    y = z + y  # pass
+    return y
diff --git a/python/testSrc/com/jetbrains/python/inspections/PyAugmentAssignmentInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/PyAugmentAssignmentInspectionTest.java
index 3ad5432d4543..fc87de23f50f 100644
--- a/python/testSrc/com/jetbrains/python/inspections/PyAugmentAssignmentInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/PyAugmentAssignmentInspectionTest.java
@@ -47,6 +47,11 @@ public class PyAugmentAssignmentInspectionTest extends PyTestCase {
     doTest();
   }
 
+  // PY-7605
+  public void testStrOrUnknownFirstArg() {
+    doTest();
+  }
+
   private void doTest() {
     myFixture.configureByFile("inspections/PyAugmentAssignmentInspection/" + getTestName(true) + ".py");
     myFixture.enableInspections(PyAugmentAssignmentInspection.class);