zero size image bugfix

src/amscimglib4/amscimglib4_image.c

@@ -90,6 +90,21 @@ AMSCIMGLIB4_API int amscimglib4_image_resize(amscimglib4_image *imgptr, int _siz
         return amscimglib4_failure;
     }
 
+    //handle zero size images
+    if(_sizex<0) _sizex = 0;
+    if(_sizey<0) _sizey = 0;
+    if(_sizex == 0 || _sizey == 0)
+    {
+      imgptr->sizex = 0;
+      imgptr->sizey = 0;
+      if(imgptr->data != NULL)
+      {
+        free(imgptr->data);
+        imgptr->data = NULL;
+      }
+      return amscimglib4_success;
+    }
+
     newdata = (unsigned char*) malloc(sizeof(unsigned char)*4*_sizex*_sizey);
     if(newdata==NULL)
     {
@@ -109,7 +124,7 @@ AMSCIMGLIB4_API int amscimglib4_image_resize(amscimglib4_image *imgptr, int _siz
             newdata[4*(I+_sizex*J)+K] = imgptr->data[4*(I+imgptr->sizex*J)+K];
     }
 
-    free(imgptr->data);
+    if(imgptr->data != NULL) {free(imgptr->data); imgptr->data = NULL; }
     imgptr->data = newdata;
     imgptr->sizex = _sizex;
     imgptr->sizey = _sizey;

src/amscimglib4/amscimglib4_tests.c

@@ -19,6 +19,11 @@ void amscimglib4_test_init()
     
     res = amscimglib4_image_resize(img1,500,500); printf("res=%d (%d,%d)\n",res,img1->sizex,img1->sizey);
     res = amscimglib4_image_copy(img2,img1); printf("res=%d, img2=(%d,%d), img1=(%d,%d)\n",res, img2->sizex,img2->sizey,img1->sizex,img1->sizey);
+    res = amscimglib4_image_resize(img1,-10,3); printf("res=%d (%d,%d)\n",res,img1->sizex,img1->sizey);
+    res = amscimglib4_image_resize(img1,0,0); printf("res=%d (%d,%d)\n",res,img1->sizex,img1->sizey);
+    res = amscimglib4_image_copy(img2,img1); printf("res=%d, img2=(%d,%d), img1=(%d,%d)\n",res, img2->sizex,img2->sizey,img1->sizex,img1->sizey);
+    
+
 
     amscimglib4_image_delete(&img1);
     amscimglib4_image_delete(&img2);

src/main.cpp

@@ -5,7 +5,7 @@ int main(int argc, char* argv[])
 {
     int ret = 0;
 
-    //amscimglib4_test_init();
+    amscimglib4_test_init();
     amscimglib4_test_loadsave();
 
     return ret;