stabilize text widget when no string is available; info message when serdisplib cannot open port

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@1192 3ae390bd-cb1e-0410-b409-cd5a39f66f1f

1 files changed, 8 insertions, 0 deletions

diff --git a/widget_text.c b/widget_text.c
index 7c1ee7a..ee178e6 100644
--- a/widget_text.c
+++ b/widget_text.c
@@ -58,6 +58,10 @@
 void widget_text_scroll(void *Self)
 {
     WIDGET *W = (WIDGET *) Self;
+    if (NULL == W || NULL == W->data) {
+        error("Warning: internal data error in Textwidget");
+        return;
+    }
     WIDGET_TEXT *T = W->data;
 
     char *prefix = P2S(&T->prefix);
@@ -68,6 +72,10 @@ void widget_text_scroll(void *Self)
     int num, len, width, pad;
     char *src, *dst;
 
+    if (NULL == string) {
+        error("Warning: Widget %s has no string", W->name);
+        return;
+    }
     num = 0;
     len = strlen(string);
     width = T->width - strlen(prefix) - strlen(postfix);