Fix #14302 FP invalidScanfArgType_int for array in struct (#8002)

Author: chrchr-github

lib/checkio.cpp

@@ -1399,7 +1399,7 @@ CheckIO::ArgumentInfo::ArgumentInfo(const Token * arg, const Settings &settings,
             for (int p = 0; p < valuetype->pointer; p++)
                 tempToken->insertToken("*");
             tempToken = const_cast<Token*>(typeToken);
-            if (top->isBinaryOp() && valuetype->pointer == 1 && (valuetype->type == ValueType::CHAR || valuetype->type == ValueType::WCHAR_T))
+            if (top->isBinaryOp() && Token::Match(top, "[+-]") && valuetype->pointer == 1 && (valuetype->type == ValueType::CHAR || valuetype->type == ValueType::WCHAR_T))
                 tempToken->tokType(Token::eString);
             return;
         }

test/testio.cpp

@@ -2186,6 +2186,12 @@ class TestIO : public TestFixture {
               "    scanf(\"%i\", \"abc\" + 1);\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:2]: (warning) %i in format string (no. 1) requires 'int *' but the argument type is 'const char *'.\n", errout_str());
+
+        check("struct S { unsigned char a[1]; };" // #14302
+              "void f(S s) {\n"
+              "    scanf(\"%hhu\", s.a);\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void testPrintfArgument() {