Added complain() on the GTK+ backend.

unix/GNUmakeinc.mk

@@ -9,6 +9,7 @@ OSCFILES = \
 	newcontrol.c \
 	parent.c \
 	tab.c \
+	text.c \
 	util.c \
 	window.c
 

unix/text.c

@@ -0,0 +1,7 @@
+// 9 april 2015
+#include "uipriv_unix.h"
+
+void uiFreeText(char *t)
+{
+	g_free(t);
+}

unix/util.c

@@ -1,7 +1,13 @@
-// 9 april 2015
+// 18 april 2015
 #include "uipriv_unix.h"
 
-void uiFreeText(char *t)
+void complain(const char *fmt, ...)
 {
-	g_free(t);
+	va_list ap;
+
+	va_start(ap, fmt);
+	// there's no g_errorv() in glib 2.32, so do it manually instead
+	g_logv(G_LOG_DOMAIN, G_LOG_LEVEL_ERROR, fmt, ap);
+	va_end(ap);
+	abort();		// just in case
 }