New 'PDC_free_memory_allocations()' frees the clipboard, SP, and plat…

…form-specific memory allocations. Also a start to fixing issue wmcbrine/PDCurses#134,  to make endwin() signal-safe (still some work to do on that front,  though.)

curses.h

@@ -41,8 +41,8 @@ Defined by this header:
 #define PDC_VER_MINOR    3
 #define PDC_VER_CHANGE   3
 #define PDC_VER_YEAR   2022
-#define PDC_VER_MONTH    06
-#define PDC_VER_DAY      26
+#define PDC_VER_MONTH    07
+#define PDC_VER_DAY      06
 
 #define PDC_STRINGIZE( x) #x
 #define PDC_stringize( x) PDC_STRINGIZE( x)
@@ -1761,6 +1761,7 @@ PDCEX  void    PDC_set_resize_limits( const int new_min_lines,
                                const int new_max_lines,
                                const int new_min_cols,
                                const int new_max_cols);
+PDCEX  void    PDC_free_memory_allocations( void);
 
 #define FUNCTION_KEY_SHUT_DOWN        0
 #define FUNCTION_KEY_PASTE            1

curspriv.h

@@ -80,6 +80,7 @@ void    PDC_scr_free(void);
 int     PDC_scr_open(void);
 void    PDC_set_keyboard_binary(bool);
 void    PDC_transform_line(int, int, int, const chtype *);
+void    PDC_free_platform_dependent_memory( void);
 const char *PDC_sysname(void);
 
 /* Internal cross-module functions */
@@ -133,4 +134,5 @@ PDCEX int PDC_wcwidth( const int32_t ucs);
 
 #define _is_altcharset( ch)  (((ch) & (A_ALTCHARSET | (A_CHARTEXT ^ 0x7f))) == A_ALTCHARSET)
 
+
 #endif /* __CURSES_INTERNALS__ */

docs/IMPLEMNT.md

@@ -1,6 +1,7 @@
 PDCurses Implementor's Guide
 ============================
 
+                2022/07/06 - added PDC_free_platform_dependent_memory()
 - Version 1.6 - 2019/09/?? - added PDC_doupdate(); removed argc, argv,
                              lines, cols and SP allocation from
                              PDC_scr_open(); removed PDC_init_pair(),
@@ -245,6 +246,12 @@ the cursor to the lower left corner. (The X11 port does nothing.)
 
 Free any memory allocated by PDC_scr_open(). Called by delscreen().
 
+### void PDC_free_platform_dependent_memory( void);
+
+Free any platform-specific memory.  Called by PDC_free_memory_allocations().
+Does nothing (at present) on all platforms except DOS and OS/2.  On those,
+it frees the initial screen state.
+
 ### int PDC_scr_open(void);
 
 The platform-specific part of initscr(). It must initialize acs_map[]

dos/pdcscrn.c

@@ -446,7 +446,7 @@ void PDC_scr_close(void)
 #endif
     PDC_LOG(("PDC_scr_close() - called\n"));
 
-    if (getenv("PDC_RESTORE_SCREEN") && saved_screen)
+    if( saved_screen)
     {
 #ifdef __DJGPP__
         dosmemput(saved_screen, saved_lines * saved_cols * 2,
@@ -463,8 +463,6 @@ void PDC_scr_close(void)
         (void *)saved_screen, (saved_lines * saved_cols * 2));
 # endif
 #endif
-        free(saved_screen);
-        saved_screen = NULL;
     }
 
     reset_shell_mode();
@@ -704,3 +702,10 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
    INTENTIONALLY_UNUSED_PARAMETER( new_min_cols);
    INTENTIONALLY_UNUSED_PARAMETER( new_max_cols);
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+    if( saved_screen)
+        free(saved_screen);
+    saved_screen = NULL;
+}

dosvga/pdcscrn.c

@@ -1735,3 +1735,7 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
                   const int new_min_cols, const int new_max_cols)
 {
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

fb/pdcscrn.c

@@ -394,3 +394,7 @@ int PDC_init_color( int color, int red, int green, int blue)
     }
     return OK;
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

os2/pdcscrn.c

@@ -59,14 +59,9 @@ void PDC_scr_close(void)
     PDC_LOG(("PDC_scr_close() - called\n"));
 
     if (saved_screen && getenv("PDC_RESTORE_SCREEN"))
-    {
         VioWrtCellStr(saved_screen, saved_lines * saved_cols * 2,
             0, 0, (HVIO)NULL);
 
-        free(saved_screen);
-        saved_screen = NULL;
-    }
-
     reset_shell_mode();
 
     if (SP->visibility != 1)
@@ -231,3 +226,10 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
                   const int new_min_cols, const int new_max_cols)
 {
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+    if( saved_screen)
+        free(saved_screen);
+    saved_screen = NULL;
+}

pdcurses/initscr.c

@@ -18,6 +18,7 @@ initscr
     SCREEN *newterm(const char *type, FILE *outfd, FILE *infd);
     SCREEN *set_term(SCREEN *new);
     void delscreen(SCREEN *sp);
+    void PDC_free_memory_allocations( void);
 
     int resize_term(int nlines, int ncols);
     bool is_termresized(void);
@@ -51,6 +52,15 @@ initscr
    needed. In PDCurses, the parameter must be the value of SP, and
    delscreen() sets SP to NULL.
 
+   PDC_free_memory_allocations() frees all memory allocated by PDCurses,
+   including SP and any platform-dependent memory.  It should be called
+   after endwin(),  not instead of it.  It need not be called,  because
+   remaining memory will be freed at exit;  but it can help in diagnosing
+   memory leak issues by ruling out any from PDCurses.
+
+   Note that SDLn and X11 have known memory leaks within their libraries,
+   which appear to be effectively unfixable.
+
    set_term() does nothing meaningful in PDCurses, but is included for
    compatibility with other curses implementations.
 
@@ -321,6 +331,13 @@ bool isendwin(void)
     return SP ? !(SP->alive) : FALSE;
 }
 
+void PDC_free_memory_allocations( void)
+{
+   PDC_free_platform_dependent_memory( );
+   PDC_clearclipboard( );
+   delscreen( SP);
+}
+
 SCREEN *newterm(const char *type, FILE *outfd, FILE *infd)
 {
     PDC_LOG(("newterm() - called\n"));

plan9/pdcscrn.c

@@ -101,3 +101,7 @@ void PDC_scr_free(void)
 {
 	free(SP);
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

sdl1/pdcscrn.c

@@ -357,3 +357,7 @@ void PDC_set_resize_limits( const int new_min_lines,
    INTENTIONALLY_UNUSED_PARAMETER( new_max_cols);
    return;
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

sdl2/pdcscrn.c

@@ -494,3 +494,7 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
    INTENTIONALLY_UNUSED_PARAMETER( new_min_cols);
    INTENTIONALLY_UNUSED_PARAMETER( new_max_cols);
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

vt/pdcscrn.c

@@ -384,3 +384,7 @@ int PDC_init_color( int color, int red, int green, int blue)
         curscr->_clear = TRUE;
     return OK;
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

wincon/pdcscrn.c

@@ -718,3 +718,7 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
     INTENTIONALLY_UNUSED_PARAMETER( new_min_cols);
     INTENTIONALLY_UNUSED_PARAMETER( new_max_cols);
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

wingui/pdcscrn.c

@@ -2422,3 +2422,7 @@ int PDC_init_color( int color, int red, int green, int blue)
     PDC_set_palette_entry( color, new_rgb);
     return OK;
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}

x11/pdcscrn.c

@@ -827,3 +827,7 @@ void PDC_set_resize_limits( const int new_min_lines, const int new_max_lines,
     PDC_min_cols = max( new_min_cols, 2);
     PDC_max_cols = max( new_max_cols, PDC_min_cols);
 }
+
+void PDC_free_platform_dependent_memory( void)
+{
+}