Merge pull request #12458 from DEEPIR:3.4

* may be an typo fix

* remove identical branch,may be paste error

* add parentheses around macro parameter

* simplify if condition

* check malloc fail

* change the condition of branch removed by commit 3041502861318c85d901e8c08226ff67898c77ed

modules/imgcodecs/src/grfmt_webp.cpp

@@ -207,9 +207,9 @@ bool WebPDecoder::readData(Mat &img)
         {
             cvtColor(read_img, img, COLOR_BGRA2BGR);
         }
-        else if (img.type() == CV_8UC3 && m_type == CV_8UC4)
+        else if (img.type() == CV_8UC4 && m_type == CV_8UC3)
         {
-            cvtColor(read_img, img, COLOR_BGRA2BGR);
+            cvtColor(read_img, img, COLOR_BGR2BGRA);
         }
         else
         {