Fix for issue 237

.github/coverage/cpp.develop.coverage_report.txt

@@ -15,7 +15,7 @@ src/DescriptorsCommand.cc                    711     110    15%   56,63-68,73,75
 src/DescriptorsManager.cc                     24      19    79%   49-50,57-58,73
 src/ExceptionsCommand.cc                       6       0     0%   35-40
 src/ImageCommand.cc                          322     157    48%   55,59,63,65,67-69,71,73-76,78,81,86,88-89,97,99,106,109,111-112,114-115,117-118,120-121,124,151,162-163,174-175,177,182-185,195-196,198,203-206,221-229,231-233,246-247,257-267,269-270,272-273,278,286,297,304,308,311,313,315,337,339-340,343-348,350,352,374-376,379-381,385-388,394,396,403-406,420,427,433-436,440-441,452-455,458-463,468-470,481-484,489-493,498-499,501-502,504-508,511,513-517,520-523,526-527,530,532,537
-src/ImageLoop.cc                             251     231    92%   63,130,182-185,215,221,265,285,288,297-298,300,307-308,322-323,330,334
+src/ImageLoop.cc                             253     232    91%   63,130,182-185,215,221,265,285,288,297-298,300,307-308,322-323,330,334,338
 src/Neo4jBaseCommands.cc                      38       0     0%   7-8,12,14-15,17,21,23-24,26,30,32-33,35,39,41-42,44,48,50,53,57-59,62-70,72,74,76-77,80
 src/Neo4JHandlerCommands.cc                  109       0     0%   50,54-55,57-58,61,65-69,72,74,76-80,82,84,86,92,95-96,98,100,102,106-107,110-111,114-119,123-124,126,128-129,132-133,137-139,141,144,149-151,155,157,160,162,165-166,169,172,176-178,180-186,188-191,196,198-201,203,206,209,211-213,217-220,222-225,228-231,233-237,239-244,249
 src/OpsIOCoordinator.cc                       96      73    76%   48,52,54-55,57,61-63,65,74,78,80,91,93,100,102-103,123,125,133,149,153,203
@@ -57,5 +57,5 @@ utils/src/comm/Exception.cc                    6       0     0%   35-40
 utils/src/stats/SystemStats.cc               250     249    99%   453
 utils/src/timers/TimerMap.cc                  82      75    91%   126,151,153,155-158
 ------------------------------------------------------------------------------
-TOTAL                                      10241    6571    64%
+TOTAL                                      10243    6572    64%
 ------------------------------------------------------------------------------

.github/coverage/cpp.develop.coverage_value.txt

@@ -1 +1 @@
-64.1637
+64.1609

remote_function/udf_server.py

@@ -56,6 +56,8 @@ def image_api():
         return_string += r_meta.encode("utf-8")
 
     os.remove(tmpfile)
+    if return_string == "" or return_string == None:
+        return "error"
     return return_string
 
 

src/ImageLoop.cc

@@ -330,6 +330,10 @@ void ImageLoop::execute_remote_operations(
         continue;
       }
       cv::Mat dmat = write_image(responseBuffer[rindex]);
+      if (dmat.rows == 0 || dmat.cols == 0) {
+        throw VCLException(ObjectEmpty,
+                           "Invalid response from the remote server.");
+      }
       if (dmat.empty()) {
         pendingImages.push_back(img);
       }