xbps: add patch to not remove non-symlinks when purging alternatives

srcpkgs/xbps/patches/56ae190.patch

@@ -0,0 +1,30 @@
+commit 56ae1907b9d588910a5e4712fdaa5784c1641f14
+Author: Duncan Overbruck <mail@duncano.de>
+Date:   Tue Aug 13 12:53:01 2019 +0200
+
+    lib/package_alternatives.c: check if alternative is a symlink before removing it
+
+diff --git lib/package_alternatives.c lib/package_alternatives.c
+index 9b4d0027..5e4f2b36 100644
+--- lib/package_alternatives.c
++++ lib/package_alternatives.c
+@@ -111,6 +111,7 @@ static int
+ remove_symlinks(struct xbps_handle *xhp, xbps_array_t a, const char *grname)
+ {
+ 	unsigned int i, cnt;
++	struct stat st;
+ 
+ 	cnt = xbps_array_count(a);
+ 	for (i = 0; i < cnt; i++) {
+@@ -132,6 +133,11 @@ remove_symlinks(struct xbps_handle *xhp, xbps_array_t a, const char *grname)
+ 		} else {
+ 			lnk = xbps_xasprintf("%s%s", xhp->rootdir, l);
+ 		}
++		if (lstat(lnk, &st) == -1 || !S_ISLNK(st.st_mode)) {
++			free(lnk);
++			free(l);
++			continue;
++		}
+ 		xbps_set_cb_state(xhp, XBPS_STATE_ALTGROUP_LINK_REMOVED, 0, NULL,
+ 		    "Removing '%s' alternatives group symlink: %s", grname, l);
+ 		unlink(lnk);

srcpkgs/xbps/template

@@ -1,7 +1,7 @@
 # Template file for 'xbps'
 pkgname=xbps
 version=0.56
-revision=6
+revision=7
 bootstrap=yes
 build_style=configure
 short_desc="XBPS package system utilities"