Index: src/hid_attrib.h
===================================================================
--- src/hid_attrib.h	(revision 11985)
+++ src/hid_attrib.h	(revision 11986)
@@ -26,11 +26,11 @@
 	PCB_HATT_LABEL,
 	PCB_HATT_INTEGER,
 	PCB_HATT_REAL,
-	PCB_HATT_STRING,              /* WARNING: must be malloc()'d, can't be a (const char *) */
+	PCB_HATT_STRING,              /* WARNING: string, must be malloc()'d, can't be a (const char *) */
 	PCB_HATT_BOOL,
 	PCB_HATT_ENUM,
 	PCB_HATT_MIXED,
-	PCB_HATT_PATH,                /* WARNING: must be malloc()'d, can't be a (const char *) */
+	PCB_HATT_PATH,                /* WARNING: string, must be malloc()'d, can't be a (const char *) */
 	PCB_HATT_UNIT,
 	PCB_HATT_COORD,
 	PCB_HATT_BUTTON,              /* push button; default value is the label */
@@ -45,6 +45,9 @@
 #define PCB_HATT_IS_COMPOSITE(type) \
 	(((type) >= PCB_HATT_BEGIN_HBOX) && ((type) < PCB_HATT_END))
 
+#define PCB_HAT_IS_STR(type) \
+	((type == PCB_HATT_STRING) || (type == PCB_HATT_PATH))
+
 /* alternative field names in struct pcb_hid_attribute_s */
 #define pcb_hatt_flags       max_val
 #define pcb_hatt_table_cols  min_val
Index: src_plugins/hid_lesstif/dialogs.c
===================================================================
--- src_plugins/hid_lesstif/dialogs.c	(revision 11985)
+++ src_plugins/hid_lesstif/dialogs.c	(revision 11986)
@@ -948,8 +948,10 @@
 		if (attrs[i].help_text != ATTR_UNDOCUMENTED)
 			ctx->actual_nattrs++;
 		results[i] = attrs[i].default_val;
-		if (results[i].str_value)
+		if (PCB_HAT_IS_STR(attrs[i].type) && (results[i].str_value))
 			results[i].str_value = pcb_strdup(results[i].str_value);
+		else
+			results[i].str_value = NULL;
 	}
 
 	ctx->wl = (Widget *) calloc(n_attrs, sizeof(Widget));
Index: src_plugins/lib_gtk_common/dlg_attribute.c
===================================================================
--- src_plugins/lib_gtk_common/dlg_attribute.c	(revision 11985)
+++ src_plugins/lib_gtk_common/dlg_attribute.c	(revision 11986)
@@ -576,8 +576,10 @@
 		int i;
 		for (i = 0; i < ctx->n_attrs; i++) {
 			ctx->results[i] = ctx->attrs[i].default_val;
-			if (ctx->results[i].str_value)
+			if (PCB_HAT_IS_STR(ctx->attrs[i].type) && (ctx->results[i].str_value))
 				ctx->results[i].str_value = pcb_strdup(ctx->results[i].str_value);
+			else
+				ctx->results[i].str_value = NULL;
 		}
 	}