make panel_hidden portable

fixing #325 while being a breaking change returning TRUE (1) and FALSE (0) instead of OK (0) and ERR (-1)

demos/test_pan.c

@@ -279,11 +279,7 @@ int main( const int argc, const char **argv)
          case 9:
             if( curr_top)
                {
-#ifdef __PDCURSES__
                if( panel_hidden( curr_top) == OK)
-#else
-               if( panel_hidden( curr_top) == TRUE)
-#endif
                   show_panel( curr_top);
                else
                   hide_panel( curr_top);

docs/HISTORY.md

@@ -1,7 +1,7 @@
 Generally speaking,  this history mentions only the more significant
 changes.  See the git log for full details.
 
-Current PDCursesMod - 2024 Oct 28
+Current PDCursesMod - 2024 Dec 31
 =================================
 
 Major new features
@@ -54,6 +54,8 @@ Minor new features
   arbitrarily long strings via recursion.  Added some code to test this
   in 'show_col.c'.  3f8dfa9e06   18ef78de69
 
+- PDC_wcwidth( ) updated from Unicode 14.0.0 to 16.0.0   93e32ef a5f13c2
+
 Bug fixes
 ---------
 
@@ -119,6 +121,10 @@ Bug fixes
 - Fixes for Borland Turbo C compilation. a59f452e78  26128c29aa
   d6b7e998eb
 
+- panel_hidden() is now portable, returning TRUE (1) and FALSE (0) instead
+  of OK (0) and ERR (-1) This may break existing applications, so you possibly
+  want to check for the PDCurses version number / date.
+
 PDCursesMod 4.4.0 - 2023 November 30
 ===================================
 

pdcurses/panel.c

@@ -71,7 +71,8 @@ panel
 
    ceiling_panel() returns a pointer to the top panel in the deck.
 
-   panel_hidden() returns OK if pan is hidden and ERR if it is not.
+   panel_hidden() returns TRUE if pan is hidden, FALSE if not and
+   ERR if pan is NULL.
 
    panel_userptr() - Each panel has a user pointer available for
    maintaining relevant information. This function returns a pointer to
@@ -430,11 +431,10 @@ PANEL *ground_panel( SCREEN *sp)
 
 int panel_hidden(const PANEL *pan)
 {
-    assert( pan);
     if (!pan)
         return ERR;
 
-    return _panel_is_linked(pan) ? ERR : OK;
+    return _panel_is_linked(pan) ? FALSE : TRUE;
 }
 
 const void *panel_userptr(const PANEL *pan)