From 4739f4af93347ed0fb9c4cc0032129fc559bd08c Mon Sep 17 00:00:00 2001
From: Andrew Chin <achin@eminence32.net>
Date: Tue, 22 Nov 2011 12:25:02 -0500
Subject: [PATCH] More specific rendermode error messages

---
 overviewer_core/src/iterate.c     |  3 ++-
 overviewer_core/src/rendermodes.c | 10 +++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/overviewer_core/src/iterate.c b/overviewer_core/src/iterate.c
index c6d8652..5b62941 100644
--- a/overviewer_core/src/iterate.c
+++ b/overviewer_core/src/iterate.c
@@ -373,7 +373,8 @@ chunk_render(PyObject *self, PyObject *args) {
     state.rendermode = rendermode = render_mode_create(PyString_AsString(rendermode_py), &state);
     Py_DECREF(rendermode_py);
     if (rendermode == NULL) {
-        return PyErr_Format(PyExc_ValueError, "Failed to create render mode");
+        return NULL; // note that render_mode_create will
+                     // set PyErr.  No need to set it here
     }
 
     /* get the image size */
diff --git a/overviewer_core/src/rendermodes.c b/overviewer_core/src/rendermodes.c
index dd0848f..ceaf9d4 100644
--- a/overviewer_core/src/rendermodes.c
+++ b/overviewer_core/src/rendermodes.c
@@ -124,23 +124,23 @@ RenderMode *render_mode_create(const char *mode, RenderState *state) {
     
     iface = render_mode_find_interface(mode);
     if (iface == NULL)
-        return NULL;
+        return PyErr_Format(PyExc_RuntimeError, "Failed to find rendermode interface");
     
     options = render_mode_create_options(mode);
     if (options == NULL)
-        return NULL;
+        return PyErr_Format(PyExc_RuntimeError, "Failed to create rendermode options");
     
     ret = calloc(1, sizeof(RenderMode));
     if (ret == NULL) {
         Py_DECREF(options);
-        return NULL;
+        return PyErr_Format(PyExc_RuntimeError, "Failed to alloc a rendermode");
     }
     
     ret->mode = calloc(1, iface->data_size);
     if (ret->mode == NULL) {
         Py_DECREF(options);
         free(ret);
-        return NULL;
+        return PyErr_Format(PyExc_RuntimeError, "Failed to alloc rendermode data");
     }
     
     ret->iface = iface;
@@ -150,7 +150,7 @@ RenderMode *render_mode_create(const char *mode, RenderState *state) {
         Py_DECREF(options);
         free(ret->mode);
         free(ret);
-        return NULL;
+        return PyErr_Format(PyExc_RuntimeError, "Failed to start rendermode interface");
     }
     
     Py_DECREF(options);