From 56d4f875b4329f6785f0438b9b03bb5f372d5634 Mon Sep 17 00:00:00 2001
From: Vadim Pisarevsky <no@email>
Date: Sat, 4 Dec 2010 15:35:34 +0000
Subject: [PATCH] make watershed demo work correctly

---
 modules/core/src/drawing.cpp | 2 +-
 samples/cpp/watershed.cpp    | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/modules/core/src/drawing.cpp b/modules/core/src/drawing.cpp
index 56cac1515a..ada9e7ad90 100644
--- a/modules/core/src/drawing.cpp
+++ b/modules/core/src/drawing.cpp
@@ -2033,7 +2033,7 @@ cvDrawContours( void* _img, CvSeq* contour,
     scalarToRawData( externalColor, ext_buf, img.type(), 0 );
     scalarToRawData( holeColor, hole_buf, img.type(), 0 );
 
-    maxLevel = MAX(maxLevel, INT_MIN-2);
+    maxLevel = MAX(maxLevel, INT_MIN+2);
     maxLevel = MIN(maxLevel, INT_MAX-1);
     
     if( maxLevel < 0 )
diff --git a/samples/cpp/watershed.cpp b/samples/cpp/watershed.cpp
index 955eaf246f..4e31b19483 100644
--- a/samples/cpp/watershed.cpp
+++ b/samples/cpp/watershed.cpp
@@ -86,6 +86,8 @@ int main( int argc, char** argv )
             
             findContours(markerMask, contours, hierarchy, CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);
             
+            if( contours.empty() )
+                continue;
             Mat markers(markerMask.size(), CV_32S);
             markers = Scalar::all(0);
             int idx = 0;