throw exception from c++ GdalAccessor instead of exit(1)

Leads to an OSError being thrown instead of shutting down the whole program

components/iscesys/ImageApi/DataAccessor/bindings/DataAccessormodule.cpp

@@ -135,9 +135,19 @@ createAccessor_C(PyObject* self, PyObject* args)
     exit(1);
   }
   if (casterCh[0] == '\0')
+  {
+  try
   {
     ptDataAccessor = (uint64_t) AF->createAccessor(filename, filemode, size,
         bands, width, scheme);
+  }
+  catch(const std::exception& e)
+  {
+    std::cerr << e.what() << '\n';
+    PyErr_SetString(PyExc_OSError, "Failed to created DataAccessor.");
+    return NULL;
+  }
+
   }
   else if (casterCh[0] != '\0' && PyDict_Size(dict) == 0)
   {

components/iscesys/ImageApi/InterleavedAccessor/include/GDALAccessor.h

@@ -9,6 +9,7 @@
 #endif
 
 #include <iostream>
+#include <stdexcept>
 #include "InterleavedBase.h"
 #include <stdint.h>
 #include "gdal_priv.h"

components/iscesys/ImageApi/InterleavedAccessor/src/GDALAccessor.cpp

@@ -71,10 +71,11 @@ GDALAccessor::openFile (string filename, string accessMode, GDALDataset ** fd)
         std::cout << "GDAL open (R): " << filename << std::endl;
 	(*fd) = (GDALDataset *) GDALOpenShared (filename.c_str (), GA_ReadOnly);
 	if ((*fd) == NULL)
-	{
+    {
 	    cout << "Error. Cannot open the file " << filename << " in "
 		    << accessMode << " mode." << endl;
-	    ERR_MESSAGE
+        throw runtime_error("GDAL file open error.");
+	    // ERR_MESSAGE
 	    ;
 	}
     }