discard_hba_and_ident_cxt_1.patch

diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index f1e9a38..a4b47a8 100644
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -1813,8 +1813,7 @@ load_hba(void)
 	FreeFile(file);
 
 	/* Now parse all the lines */
-	Assert(PostmasterContext);
-	hbacxt = AllocSetContextCreate(PostmasterContext,
+	hbacxt = AllocSetContextCreate(CurrentMemoryContext,
 								   "hba parser context",
 								   ALLOCSET_SMALL_SIZES);
 	oldcxt = MemoryContextSwitchTo(hbacxt);
@@ -1870,14 +1869,24 @@ load_hba(void)
 	}
 
 	/* Loaded new file successfully, replace the one we use */
-	if (parsed_hba_context != NULL)
-		MemoryContextDelete(parsed_hba_context);
+	discard_hba();
 	parsed_hba_context = hbacxt;
 	parsed_hba_lines = new_parsed_lines;
 
 	return true;
 }
 
+void
+discard_hba(void)
+{
+	if (parsed_hba_context != NULL)
+	{
+		MemoryContextDelete(parsed_hba_context);
+		parsed_hba_context = NULL;
+		parsed_hba_lines = NIL;
+	}
+}
+
 /*
  * Parse one tokenised line from the ident config file and store the result in
  * an IdentLine structure, or NULL if parsing fails.
@@ -2189,8 +2198,7 @@ load_ident(void)
 	FreeFile(file);
 
 	/* Now parse all the lines */
-	Assert(PostmasterContext);
-	ident_context = AllocSetContextCreate(PostmasterContext,
+	ident_context = AllocSetContextCreate(CurrentMemoryContext,
 										  "ident parser context",
 										  ALLOCSET_SMALL_SIZES);
 	oldcxt = MemoryContextSwitchTo(ident_context);
@@ -2241,6 +2249,19 @@ load_ident(void)
 	}
 
 	/* Loaded new file successfully, replace the one we use */
+	discard_ident();
+	parsed_ident_context = ident_context;
+	parsed_ident_lines = new_parsed_lines;
+
+	return true;
+}
+
+void
+discard_ident(void)
+{
+	ListCell   *parsed_line_cell;
+	IdentLine  *newline;
+
 	if (parsed_ident_lines != NIL)
 	{
 		foreach(parsed_line_cell, parsed_ident_lines)
@@ -2249,14 +2270,14 @@ load_ident(void)
 			if (newline->ident_user[0] == '/')
 				pg_regfree(&newline->re);
 		}
+		parsed_ident_lines = NIL;
 	}
+
 	if (parsed_ident_context != NULL)
+	{
 		MemoryContextDelete(parsed_ident_context);
-
-	parsed_ident_context = ident_context;
-	parsed_ident_lines = new_parsed_lines;
-
-	return true;
+		parsed_ident_context = NULL;
+	}
 }
 
 
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 824d5ab..b93b307 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -192,17 +192,6 @@ PerformAuthentication(Port *port)
 	 * FIXME: [fork/exec] Ugh.  Is there a way around this overhead?
 	 */
 #ifdef EXEC_BACKEND
-
-	/*
-	 * load_hba() and load_ident() want to work within the PostmasterContext,
-	 * so create that if it doesn't exist (which it won't).  We'll delete it
-	 * again later, in PostgresMain.
-	 */
-	if (PostmasterContext == NULL)
-		PostmasterContext = AllocSetContextCreate(TopMemoryContext,
-												  "Postmaster",
-												  ALLOCSET_DEFAULT_SIZES);
-
 	if (!load_hba())
 	{
 		/*
@@ -738,6 +727,14 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 	}
 
 	/*
+	 * We don't need the HBA and ident data going forward, but we can't rely
+	 * on release of PostmasterContext to clean that up, so discard them
+	 * explicitly here.
+	 */
+	discard_hba();
+	discard_ident();
+
+	/*
 	 * If we're trying to shut down, only superusers can connect, and new
 	 * replication connections are not allowed.
 	 */
diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h
index dc7d257..d0a8ad2 100644
--- a/src/include/libpq/hba.h
+++ b/src/include/libpq/hba.h
@@ -102,6 +102,10 @@ typedef struct Port hbaPort;
 
 extern bool load_hba(void);
 extern bool load_ident(void);
+
+extern void discard_hba(void);
+extern void discard_ident(void);
+
 extern void hba_getauthmethod(hbaPort *port);
 extern int check_usermap(const char *usermap_name,
 			  const char *pg_role, const char *auth_user,