Fix #1599 (false positive on if( (f = fopen("foo", "r")) == ((FILE*)NULL) ))

http://sourceforge.net/apps/trac/cppcheck/ticket/1599

lib/tokenize.cpp

@@ -3190,16 +3190,6 @@ bool Tokenizer::simplifyTokenList()
         }
     }
 
-    // Replace pointer casts of 0.. "(char *)0" => "0"
-    for (Token *tok = _tokens; tok; tok = tok->next())
-    {
-        if (Token::Match(tok->next(), "( %type% * ) 0") ||
-            Token::Match(tok->next(), "( %type% %type% * ) 0"))
-        {
-            Token::eraseTokens(tok, tok->next()->link()->next());
-        }
-    }
-
     // Change initialisation of variable to assignment
     simplifyInitVar();
 
@@ -3947,6 +3937,19 @@ void Tokenizer::simplifyCasts()
             }
         }
 
+        // Replace pointer casts of 0.. "(char *)0" => "0"
+        while (Token::Match(tok->next(), "( %type% * ) 0") ||
+               Token::Match(tok->next(), "( %type% %type% * ) 0"))
+        {
+            Token::eraseTokens(tok, tok->next()->link()->next());
+            if (tok->str() == ")" && tok->link()->previous())
+            {
+                // If there was another cast before this, go back
+                // there to check it also. e.g. "(char*)(char*)0"
+                tok = tok->link()->previous();
+            }
+        }
+
         if (Token::Match(tok->next(), "dynamic_cast|reinterpret_cast|const_cast|static_cast <"))
         {
             Token *tok2 = tok->next();

test/testsimplifytokens.cpp

@@ -105,6 +105,7 @@ private:
 
         // Assignment in condition..
         TEST_CASE(ifassign1);
+        TEST_CASE(ifAssignWithCast);
         TEST_CASE(whileAssign);
 
         // "if(0==x)" => "if(!x)"
@@ -294,6 +295,7 @@ private:
         ASSERT_EQUALS("if ( * a )", tok("if ((unsigned int)(unsigned char)*a)"));
         ASSERT_EQUALS("class A { A operator * ( int ) ; } ;", tok("class A { A operator *(int); };"));
         ASSERT_EQUALS("class A { A operator * ( int ) const ; } ;", tok("class A { A operator *(int) const; };"));
+        ASSERT_EQUALS("if ( ! p )", tok("if (p == (char *)(char *)0)"));
     }
 
 
@@ -1861,6 +1863,27 @@ private:
         TODO_ASSERT_EQUALS("void foo ( A a ) { a . c = b ( ) ; if ( 0 <= a . c ) { ; } }", tok("void foo(A a) {if((a.c=b())>=0);}"));
     }
 
+    void ifAssignWithCast()
+    {
+        const char *code =  "void foo()\n"
+                            "{\n"
+                            "FILE *f;\n"
+                            "if( (f = fopen(\"foo\", \"r\")) == ((FILE*)NULL) )\n"
+                            "return(-1);\n"
+                            "fclose(f);\n"
+                            "}\n";
+        const char *exptected = "void foo ( ) "
+                                "{ "
+                                "FILE * f ; "
+                                "f = fopen ( \"foo\" , \"r\" ) ; "
+                                "if ( ! f ) "
+                                "{ "
+                                "return -1 ; "
+                                "} "
+                                "fclose ( f ) ; "
+                                "}";
+        ASSERT_EQUALS(exptected, tok(code));
+    }
 
     void whileAssign()
     {