Oh wow. A bunch of regrets here:

1. Use specific methods, like `OSRDestroySpatialReference`, over generic ones, like
`OSRRelease`. The specific ones are always right.
2. `atexit` is always a mistake.
3. Questions end with a question mark.

src/init.c

@@ -5,20 +5,16 @@
 
 static int initialized = 0;
 
-// The atexit handler used to close all connections to open data stores
-static void cleanup() {
-  OGRCleanupAll();
-}
-
 // Initialize libraries, register the atexit handler and set up error reporting.
 void simplet_init() {
   if (initialized) return;
   CPLSetConfigOption("OGR_ENABLE_PARTIAL_REPROJECTION", "ON");
 #ifdef DEBUG
   CPLSetConfigOption("CPL_DEBUG", "ON");
+#else
+  CPLSetConfigOption("CPL_DEBUG", "OFF");
 #endif
   OGRRegisterAll();
   GDALAllRegister();
-  atexit(cleanup);
   initialized = 1;
 };

src/map.c

@@ -59,7 +59,7 @@ void simplet_map_free(simplet_map_t *map) {
     simplet_list_free(map->layers);
   }
 
-  if (map->proj) OSRRelease(map->proj);
+  if (map->proj) OSRDestroySpatialReference(map->proj);
 
   if (map->bgcolor) free(map->bgcolor);
 
@@ -248,7 +248,7 @@ const char *simplet_map_status_to_string(simplet_map_t *map) {
 
 // Check if the map is valid for rendering
 simplet_status_t simplet_map_is_valid(simplet_map_t *map) {
-  // Does it have a previously set error.
+  // Does it have a previously set error?
   if (!(map->status == SIMPLET_OK)) return SIMPLET_ERR;
 
   // Does it have a bounds?

src/query.c

@@ -216,6 +216,7 @@ simplet_status_t simplet_query_process(simplet_query_t *query,
   if (!(olayer = OGR_DS_ExecuteSQL(source, query->ogrsql, NULL, NULL))) {
     int err = CPLGetLastErrorNo();
     if (!err) {
+      // FIXME: This should be a problem, but it is ignored right now.
       return SIMPLET_OK;
     } else {
       return set_error(query, SIMPLET_OGR_ERR, CPLGetLastErrorMsg());

src/vector_layer.c

@@ -80,9 +80,6 @@ simplet_status_t simplet_vector_layer_process(simplet_vector_layer_t *layer,
   if (!(source = OGROpenShared(layer->source, 0, NULL)))
     return set_error(layer, SIMPLET_OGR_ERR, "error opening layer source");
 
-  // Retain the datasource because we want to cache open connections to a
-  // data source like postgres.
-  if (OGR_DS_GetRefCount(source) == 1) OGR_DS_Reference(source);
   if (!(iter = simplet_get_list_iter(layer->queries))) {
     OGRReleaseDataSource(source);
     return set_error(layer, SIMPLET_OOM, "out of memory getting list iterator");