libxdg-basedir overflow fix

Hi,

The libxdg-basedir package has an overflow bug. This causes
games/openttd to crash on startup if "sysctl vm.malloc_conf=C" (or S).

Upstream fixed the bug in 2014. However, the latest release is
libxdg-basedir-1.2.0, which in three weeks will be eight years old.

ok?

Index: Makefile
===================================================================
RCS file: /cvs/ports/x11/libxdg-basedir/Makefile,v
retrieving revision 1.10
diff -u -p -r1.10 Makefile
--- Makefile 12 Jul 2019 20:51:15 -0000 1.10
+++ Makefile 3 Jan 2020 10:38:25 -0000
@@ -5,7 +5,7 @@ COMMENT = implementation of the XDG Base
DISTNAME = libxdg-basedir-1.2.0
SHARED_LIBS += xdg-basedir 2.0 # .3.0
CATEGORIES = x11 devel
-REVISION = 1
+REVISION = 2

# MIT
PERMIT_PACKAGE = Yes
Index: patches/patch-src_basedir_c
===================================================================
RCS file: /cvs/ports/x11/libxdg-basedir/patches/patch-src_basedir_c,v
retrieving revision 1.2
diff -u -p -r1.2 patch-src_basedir_c
--- patches/patch-src_basedir_c 15 Dec 2010 13:22:03 -0000 1.2
+++ patches/patch-src_basedir_c 3 Jan 2020 10:38:25 -0000
@@ -1,6 +1,9 @@
$OpenBSD: patch-src_basedir_c,v 1.2 2010/12/15 13:22:03 dcoppa Exp $
---- src/basedir.c.orig Tue Jul 13 07:48:54 2010
-+++ src/basedir.c Wed Dec 15 14:13:49 2010
+Overflow fix from upstream:
+https://github.com/devnev/libxdg-basedir/commit/14e000f696ef8b83264b0ca4407669bdb365fb23
+Index: src/basedir.c
+--- src/basedir.c.orig
++++ src/basedir.c
@@ -91,13 +91,12 @@ static void xdgZeroMemory(void* p, int n)
static const char
DefaultRelativeDataHome[] = DIR_SEPARATOR_STR ".local" DIR_SEPARATOR_STR "share",
@@ -18,3 +21,12 @@ $OpenBSD: patch-src_basedir_c,v 1.2 2010
*DefaultConfigDirectoriesList[] = { DefaultConfigDirectories, NULL };

typedef struct _xdgCachedData
+@@ -574,7 +573,7 @@ static char * xdgGetRelativeHome(const char *envname,
+ unsigned int homelen;
+ if (!(home = xdgGetEnv("HOME")))
+ return NULL;
+- if (!(relhome = (char*)malloc((homelen = strlen(home))+fallbacklength))) return NULL;
++ if (!(relhome = (char*)malloc((homelen = strlen(home))+fallbacklength+1))) return NULL;
+ memcpy(relhome, home, homelen);
+ memcpy(relhome+homelen, relativefallback, fallbacklength+1);
+ }