From: Michał Kępień
Date: Mon, 13 Jan 2020 05:03:00 +0000
Subject: Handle catopen() errors

musl libc's implementation of catgets() crashes when its first argument
is -1 instead of a proper message catalog descriptor.  Prevent that from
happening by making isc_msgcat_get() return the default text if the
prior call to catopen() returns an error.

Porting forward upstream's fix:
https://gitlab.isc.org/isc-projects/bind9/-/commit/daade37977fafee12c7b3c1483516e010d2b74a6

---

--- a/bind/bind-9.11.14/lib/isc/nls/msgcat.c
+++ b/bind/bind-9.11.14/lib/isc/nls/msgcat.c
@@ -62,9 +62,8 @@
 
 #ifdef HAVE_CATGETS
 	/*
-	 * We don't check if catopen() fails because we don't care.
-	 * If it does fail, then when we call catgets(), it will use
-	 * the default string.
+	 * We don't check if catopen() fails because isc_msgcat_get() takes
+	 * care of that before calling catgets().
 	 */
 	msgcat->catalog = catopen(name, 0);
 #endif
@@ -112,7 +111,7 @@
 	REQUIRE(default_text != NULL);
 
 #ifdef HAVE_CATGETS
-	if (msgcat == NULL)
+	if (msgcat == NULL || msgcat->catalog == (nl_catd)(-1))
 		return (default_text);
 	return (catgets(msgcat->catalog, set, message, default_text));
 #else