[postgis-tickets] r15210 - raster GUC - boot_postgis_gdal_enabled_drivers should use TopMemoryContext instead of CurrentMemoryContext

[Regina Obe]

Author: robe
Date: 2016-10-15 22:36:26 -0700 (Sat, 15 Oct 2016)
New Revision: 15210

Modified:
   branches/2.2/NEWS
   branches/2.2/raster/rt_pg/rtpostgis.c
Log:
raster GUC - boot_postgis_gdal_enabled_drivers should use TopMemoryContext instead of CurrentMemoryContext
Closes #3659  for 2.2 (PostGIS 2.2.4) patch provided by manaeem

Modified: branches/2.2/NEWS
===================================================================
--- branches/2.2/NEWS	2016-10-16 01:16:42 UTC (rev 15209)
+++ branches/2.2/NEWS	2016-10-16 05:36:26 UTC (rev 15210)
@@ -4,6 +4,8 @@
  * Bug Fixes *
 
  - #3656, Fix upgrade of aggregates from 2.2 or lower version
+ - #3659, Crash caused by raster GUC define after CREATE EXTENSION
+     using wrong memory context. (manaeem)
 
 
 PostGIS 2.2.3

Modified: branches/2.2/raster/rt_pg/rtpostgis.c
===================================================================
--- branches/2.2/raster/rt_pg/rtpostgis.c	2016-10-16 01:16:42 UTC (rev 15209)
+++ branches/2.2/raster/rt_pg/rtpostgis.c	2016-10-16 05:36:26 UTC (rev 15210)
@@ -132,6 +132,7 @@
 #include <postgres.h> /* for palloc */
 #include <fmgr.h> /* for PG_MODULE_MAGIC */
 #include "utils/guc.h"
+#include "utils/memutils.h"
 
 #include "../../postgis_config.h"
 #include "lwgeom_pg.h"
@@ -151,6 +152,9 @@
 /* Module load callback */
 void _PG_init(void);
 
+/* Module unload callback */
+void _PG_fini(void);
+
 #define RT_MSG_MAXLEN 256
 
 
@@ -244,6 +248,14 @@
 extern char *gdal_enabled_drivers;
 extern char enable_outdb_rasters;
 
+/* ---------------------------------------------------------------- */
+/*  Useful variables                                                */
+/* ---------------------------------------------------------------- */
+
+static char *env_postgis_gdal_enabled_drivers = NULL;
+static char *boot_postgis_gdal_enabled_drivers = NULL;
+static char *env_postgis_enable_outdb_rasters = NULL;
+
 /* postgis.gdal_datapath */
 static void
 rtpg_assignHookGDALDataPath(const char *newpath, void *extra) {
@@ -408,11 +420,8 @@
 void
 _PG_init(void) {
 
-	char *env_postgis_gdal_enabled_drivers = NULL;
-	char *boot_postgis_gdal_enabled_drivers = NULL;
-
-	char *env_postgis_enable_outdb_rasters = NULL;
 	bool boot_postgis_enable_outdb_rasters = false;
+	MemoryContext old_context;
 
 	/* Install liblwgeom handlers */
 	pg_install_lwgeom_handlers();
@@ -421,6 +430,12 @@
 	rt_set_handlers(rt_pg_alloc, rt_pg_realloc, rt_pg_free, rt_pg_error, rt_pg_debug, rt_pg_notice);
 
 	/*
+	 * Change to context for memory allocation calls like palloc() in the
+	 * extension initialization routine
+	 */
+	old_context = MemoryContextSwitchTo(TopMemoryContext);
+
+	/*
 	 use POSTGIS_GDAL_ENABLED_DRIVERS to set the bootValue
 	 of GUC postgis.gdal_enabled_drivers
 	*/
@@ -513,6 +528,27 @@
 		NULL  /* GucShowHook show_hook */
 	);
 
-	/* free memory allocations */
+	/* Revert back to old context */
+	MemoryContextSwitchTo(old_context);
+}
+
+/* Module unload callback */
+void
+_PG_fini(void) {
+
+	MemoryContext old_context;
+
+	old_context = MemoryContextSwitchTo(TopMemoryContext);
+
+	/* Clean up */
+	pfree(env_postgis_gdal_enabled_drivers);
 	pfree(boot_postgis_gdal_enabled_drivers);
+	pfree(env_postgis_enable_outdb_rasters);
+
+	env_postgis_gdal_enabled_drivers = NULL;
+	boot_postgis_gdal_enabled_drivers = NULL;
+	env_postgis_enable_outdb_rasters = NULL;
+
+	/* Revert back to old context */
+	MemoryContextSwitchTo(old_context);
 }