fix for #2901 (en exception was raised when getting empty MatOfDMatch)

diff --git a/modules/java/generator/src/java/core+MatOfDMatch.java b/modules/java/generator/src/java/core+MatOfDMatch.java
index 7a3094933c5f52a26a7a25292a988e104c62c56a..4a161017d404cb686fffa32eb9ff715f09ab5558 100644 (file)
--- a/modules/java/generator/src/java/core+MatOfDMatch.java
+++ b/modules/java/generator/src/java/core+MatOfDMatch.java
@@ -16,8 +16,8 @@ public class MatOfDMatch extends Mat {
 
     protected MatOfDMatch(long addr) {
         super(addr);
-        if(checkVector(_channels, _depth) < 0 )
-            throw new IllegalArgumentException("Incomatible Mat");
+        if( !empty() && checkVector(_channels, _depth) < 0 )
+            throw new IllegalArgumentException("Incomatible Mat: " + toString());
         //FIXME: do we need release() here?
     }
 
@@ -27,8 +27,8 @@ public class MatOfDMatch extends Mat {
 
     public MatOfDMatch(Mat m) {
         super(m, Range.all());
-        if(checkVector(_channels, _depth) < 0 )
-            throw new IllegalArgumentException("Incomatible Mat");
+        if( !empty() && checkVector(_channels, _depth) < 0 )
+            throw new IllegalArgumentException("Incomatible Mat: " + toString());
         //FIXME: do we need release() here?
     }