Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/core/src/system.cpp

@@ -804,7 +804,7 @@ String format( const char* fmt, ... )
         va_list va;
         va_start(va, fmt);
         int bsize = static_cast<int>(buf.size());
-        int len = cv_vsnprintf((char *)buf, bsize, fmt, va);
+        int len = cv_vsnprintf(buf.data(), bsize, fmt, va);
         va_end(va);
 
         CV_Assert(len >= 0 && "Check format string for errors");
@@ -814,7 +814,7 @@ String format( const char* fmt, ... )
             continue;
         }
         buf[bsize - 1] = 0;
-        return String((char *)buf, len);
+        return String(buf.data(), len);
     }
 }