dlt-user: fix invalid return in dlt_user_log_write_start_internal

dlt_user_log_write_start_internal might return OK when the buffer
was not initalized, this can lead to other functions assuming that
the buffer was setup correctly and thus access invalid memory.

Signed-off-by: Alexander Mohr <alexander.m.mohr@mercedes-benz.com>

Author: alexmohr

src/lib/dlt_user.c

@@ -1838,7 +1838,7 @@ DltReturnValue dlt_user_log_write_start_internal(DltContext *handle,
         return DLT_RETURN_WRONG_PARAMETER;
     } else if (ret == DLT_RETURN_LOGGING_DISABLED) {
         log->handle = NULL;
-        return DLT_RETURN_OK;
+        return ret;
     }
 
     ret = dlt_user_log_write_start_init(handle, log, loglevel, is_verbose);

tests/gtest_dlt_user.cpp

@@ -173,11 +173,11 @@ TEST(t_dlt_user_log_write_start, normal)
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start(&context, &contextData, DLT_LOG_INFO));
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_finish(&contextData));
     /* To test the default behaviour and the default log level set to DLT_LOG_INFO */
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start(&context, &contextData, DLT_LOG_OFF));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start(&context, &contextData, DLT_LOG_OFF));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start(&context, &contextData, DLT_LOG_DEBUG));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start(&context, &contextData, DLT_LOG_DEBUG));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start(&context, &contextData, DLT_LOG_VERBOSE));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start(&context, &contextData, DLT_LOG_VERBOSE));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
 
     EXPECT_LE(DLT_RETURN_OK, dlt_unregister_context(&context));
@@ -268,11 +268,11 @@ TEST(t_dlt_user_log_write_start_id, normal)
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_INFO, messageid));
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_finish(&contextData));
     /* To test the default behaviour and the default log level set to DLT_LOG_INFO */
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_OFF, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_OFF, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_DEBUG, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_DEBUG, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_VERBOSE, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_VERBOSE, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
 
     messageid = UINT32_MAX;
@@ -287,11 +287,11 @@ TEST(t_dlt_user_log_write_start_id, normal)
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_INFO, messageid));
     EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_finish(&contextData));
     /* To test the default behaviour and the default log level set to DLT_LOG_INFO */
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_OFF, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_OFF, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_DEBUG, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_DEBUG, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
-    EXPECT_LE(DLT_RETURN_OK, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_VERBOSE, messageid));
+    EXPECT_LE(DLT_RETURN_LOGGING_DISABLED, dlt_user_log_write_start_id(&context, &contextData, DLT_LOG_VERBOSE, messageid));
     EXPECT_LE(DLT_RETURN_WRONG_PARAMETER, dlt_user_log_write_finish(&contextData));
 
     EXPECT_LE(DLT_RETURN_OK, dlt_unregister_context(&context));