Fixing GCC 4.9 warning

modules/xfeatures2d/src/stardetector.cpp

@@ -144,8 +144,9 @@ StarDetectorComputeResponses( const Mat& img, Mat& responses, Mat& sizes,
 {
     const int MAX_PATTERN = 17;
     static const int sizes0[] = {1, 2, 3, 4, 6, 8, 11, 12, 16, 22, 23, 32, 45, 46, 64, 90, 128, -1};
-    static const int pairs[][2] = {{1, 0}, {3, 1}, {4, 2}, {5, 3}, {7, 4}, {8, 5}, {9, 6},
-                                   {11, 8}, {13, 10}, {14, 11}, {15, 12}, {16, 14}, {-1, -1}};
+    static const int pairs[12][2] = {{1, 0}, {3, 1}, {4, 2}, {5, 3}, {7, 4}, {8, 5}, {9, 6},
+                                     {11, 8}, {13, 10}, {14, 11}, {15, 12}, {16, 14}};
+    const int MAX_PAIR = sizeof(pairs)/sizeof(pairs[0]);
     float invSizes[MAX_PATTERN][2];
     int sizes1[MAX_PATTERN];
 
@@ -172,14 +173,15 @@ StarDetectorComputeResponses( const Mat& img, Mat& responses, Mat& sizes,
     responses.create( img.size(), CV_32F );
     sizes.create( img.size(), CV_16S );
 
-    while( pairs[npatterns][0] >= 0 && !
+    while( npatterns < MAX_PAIR && !
           ( sizes0[pairs[npatterns][0]] >= maxSize
            || sizes0[pairs[npatterns+1][0]] + sizes0[pairs[npatterns+1][0]]/2 >= std::min(rows, cols) ) )
     {
         ++npatterns;
     }
 
-    npatterns += (pairs[npatterns-1][0] >= 0);
+    if (npatterns-1 < MAX_PAIR)
+        ++npatterns;
     maxIdx = pairs[npatterns-1][0];
 
     // Create the integral image appropriate for our type & usage