Fixed #1629 (False negative: null pointer derefence not detected 'c[0] = 0')

lib/checkother.cpp

@@ -1782,7 +1782,7 @@ private:
                 bailOutVar(checks, tok.varId());
         }
 
-        if (Token::simpleMatch(&tok, "* 0"))
+        else if (Token::simpleMatch(&tok, "* 0"))
         {
             if (Token::Match(tok.previous(), "[;{}=+-/(,]") ||
                 Token::Match(tok.previous(), "return|<<"))
@@ -1795,6 +1795,15 @@ private:
             }
         }
 
+        else if (tok.str() == "delete")
+        {
+            const Token *ret = tok.next();
+            if (Token::simpleMatch(ret, "[ ]"))
+                ret = ret->tokAt(2);
+            if (Token::Match(ret, "%var% ;"))
+                return ret->next();
+        }
+
         return &tok;
     }
 

test/testother.cpp

@@ -1020,6 +1020,16 @@ private:
                          "}\n");
         ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
 
+        checkNullPointer("void f()\n"
+                         "{\n"
+                         "    char *c = 0;\n"
+                         "    {\n"
+                         "        delete c;\n"
+                         "    }\n"
+                         "    c[0] = 0;\n"
+                         "}\n");
+        ASSERT_EQUALS("[test.cpp:7]: (error) Possible null pointer dereference: c\n", errout.str());
+
         // no false positive..
         checkNullPointer("static void foo()\n"
                          "{\n"