Uninitialized variables: Fixed false positive for 'p=malloc; if (p) {}'

lib/checkuninitvar.cpp

@@ -1703,7 +1703,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
 
             } else if (Token::Match(start->previous(), "if|while|for")) {
                 // control-flow statement reading the variable "by value"
-                return true;
+                return !alloc;
             }
         }
     }
@@ -1766,7 +1766,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
 
     bool unknown = false;
     if (pointer && CheckNullPointer::isPointerDeRef(vartok, unknown)) {
-        // pointer is allocated
+        // pointer is allocated - dereferencing it is ok.
         if (alloc)
             return false;
 

test/testuninitvar.cpp

@@ -3272,6 +3272,12 @@ private:
                         "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        checkUninitVar2("void f() {\n"
+                        "    char *s = malloc(100);\n"
+                        "    if (s != NULL) { }\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
+
         // function parameter (treat it as initialized until malloc is used)
         checkUninitVar2("int f(int *p) {\n"
                         "    if (*p == 1) {}\n" // no error