Fl_String refactoring and extension (#683)

- add true unittest and Fl_String testing
- interface and printout are similar to gtest
  without requiring external linkage.
  just run `unittest --core`.
- new Fl_String API
- extended API to fl_input_str and fl_password_str
- co-authored-by: Albrecht Schlosser <albrechts.fltk@online.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/test/ask.cxx b/test/ask.cxx
index 0c2365149..973a42d11 100644
--- a/test/ask.cxx
+++ b/test/ask.cxx
@@ -34,16 +34,17 @@
 
 void rename_button(Fl_Widget *o, void *v) {
   int what = fl_int(v);
+  int ret = 0;
   Fl_String input;
   if (what == 0) {
     fl_message_icon_label("§");
-    input = fl_input_str(0, "Input (no size limit, use ctrl/j for newline):", o->label());
+    input = fl_input_str(ret, 0, "Input (no size limit, use ctrl/j for newline):", o->label());
   } else {
     fl_message_icon_label("€");
-    input = fl_password_str(20, "Enter password (max. 20 characters):", o->label());
+    input = fl_password_str(ret, 20, "Enter password (max. 20 characters):", o->label());
   }
-  if (input.value()) {
-    o->copy_label(input.value());
+  if (ret == 0) {
+    o->copy_label(input.c_str());
     o->redraw();
   }
 }