Make passing unknown fstypes to -fstype result in a warning instead of

an error.  As it was, which find command lines that would work (be
accepted at all) was dependent on the presently running kernel, making
script writing and porting hard.

usr.bin/find/function.c

@@ -564,6 +564,14 @@ f_fstype(plan, entry)
 }
 
 #if !defined(__NetBSD__)
+int
+f_always_false(plan, entry)
+	PLAN *plan;
+	FTSENT *entry;
+{
+	return (0);
+}
+
 PLAN *
 c_fstype(arg)
 	char *arg;
@@ -600,8 +608,14 @@ c_fstype(arg)
 		}
 		break;
 	}
-	errx(1, "%s: unknown file type", arg);
-	/* NOTREACHED */
+	/*
+	 * We need to make filesystem checks for filesystems
+	 * that exists but aren't in the kernel work.
+	 */
+	fprintf(stderr, "Warning: Unknown filesystem type %s\n", arg);
+	free(new);
+
+	return (palloc(N_FSTYPE, f_always_false));
 }
 #endif