From e09b0330e4557a640cd7e506286ceb9e728198ac Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Sun, 8 Jan 2012 12:17:55 +0100
Subject: [PATCH] Class: Don't warn about uninitialized union members because
 they are often combined with a second variable

---
 lib/checkclass.cpp |  7 +++++--
 test/testclass.cpp | 22 ++++++++++++++++++++--
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 2383b0f4a..e9425edd1 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -142,8 +142,11 @@ void CheckClass::constructors()
 
                     if (classNameUsed)
                         operatorEqVarError(func->token, scope->className, var->name());
-                } else if (func->access != Private)
-                    uninitVarError(func->token, scope->className, var->name());
+                } else if (func->access != Private) {
+                    const Scope *varType = var->type();
+                    if (!varType || varType->type != Scope::eUnion)
+                        uninitVarError(func->token, scope->className, var->name());
+                }
             }
         }
     }
diff --git a/test/testclass.cpp b/test/testclass.cpp
index a7fde6e92..1b27fc82a 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -81,7 +81,8 @@ private:
         TEST_CASE(uninitVarArray3D);
         TEST_CASE(uninitVarStruct1); // ticket #2172
         TEST_CASE(uninitVarStruct2); // ticket #838
-        TEST_CASE(uninitVarUnion); // ticket #3196
+        TEST_CASE(uninitVarUnion1); // ticket #3196
+        TEST_CASE(uninitVarUnion2);
         TEST_CASE(uninitMissingFuncDef);	// can't expand function in constructor
         TEST_CASE(privateCtor1);        	// If constructor is private..
         TEST_CASE(privateCtor2);        	// If constructor is private..
@@ -2560,7 +2561,7 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
-    void uninitVarUnion() { // ticket #3196
+    void uninitVarUnion1() { // ticket #3196
         checkUninitVar("class Fred\n"
                        "{\n"
                        "private:\n"
@@ -2572,6 +2573,23 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void uninitVarUnion2() {
+        // If the "data_type" is 0 it means union member "data" is invalid.
+        // So it's ok to not initialize "data".
+        // related forum: http://sourceforge.net/apps/phpbb/cppcheck/viewtopic.php?f=3&p=1806
+        checkUninitVar("union Data { int id; int *ptr; };\n"
+                       "\n"
+                       "class Fred {\n"
+                       "private:\n"
+                       "    int data_type;\n"
+                       "    Data data;\n"
+                       "public:\n"
+                       "    Fred() : data_type(0)\n"
+                       "    { }\n"
+                       "};\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void uninitMissingFuncDef() {
         // Unknown member function
         checkUninitVar("class Fred\n"