main.c, misccoms.c, preliminary fix to bug no. 315 longjmp creates segfault under Windows 10 (VS and MINGW), when WM_CLOSE is activated. Set signal handler function to cp_evloop, which leads to com_quit here, undo this function again in com_quit to avoid loops if segfault occurs in com_quit.

src/frontend/misccoms.c

@@ -41,6 +41,11 @@ extern void sh_delete_myvec(void);
 extern void sh_delvecs(void);
 #endif
 
+#ifdef HAS_WINGUI
+#include <signal.h>
+extern RETSIGTYPE sigsegv(void);
+#endif
+
 
 void
 com_quit(wordlist *wl)
@@ -52,6 +57,22 @@ com_quit(wordlist *wl)
         (wl  &&  wl->wl_word  &&  cieq(wl->wl_word, "noask"))  ||
         !cp_getvar("askquit", CP_BOOL, NULL);
 
+    /* work around a segmentation fault during LONGJMP(jbuf, 1) from
+       signal_handler.c:93 in Windows 10 upon WM_CLOSE:
+       upon seg fault directly go to com_quit via cp_evloop.
+       See winmain.c, WM_CLOSE */
+#ifdef HAS_WINGUI
+#ifdef NGDEBUG
+    /* use standard signalling */
+    signal(SIGSEGV, SIG_DFL);
+#else
+    /* Restore original signal: Allow a comment and graceful shutdown after seg fault.
+       Prevents loop if segfault occurs in com_quit and signal function has been
+       set to cp_evloop */
+    signal(SIGSEGV, (SIGNAL_FUNCTION)sigsegv);
+#endif
+#endif
+
     /* update screen and reset terminal */
     gr_clean();
     cp_ccon(FALSE);

src/winmain.c

@@ -17,6 +17,7 @@
 #include <assert.h>         // assert macro
 #include "ngspice/stringutil.h" // copy
 #include <io.h>             // _read
+//#include <VersionHelpers.h> // check for OS
 
 #include <errno.h>
 
@@ -94,6 +95,7 @@ static int HistPtr   = 0;              /* History management */
 extern bool ft_ngdebug; /* some additional debug info printed */
 extern bool ft_batchmode;
 extern FILE *flogp;     /* definition see xmain.c, stdout redirected to file */
+extern int cp_evloop(char *string);
 
 #include "winmain.h"
 
@@ -445,6 +447,12 @@ static LRESULT CALLBACK MainWindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPA
         /* Put Spice commmand "Quit" to end the program into the text buffer */
         PostSpiceCommand( "quit");
 
+        /* work around a segmentation fault during LONGJMP(jbuf, 1) from
+           signal_handler.c:93 in Windows 10 upon WM_CLOSE:
+           upon seg fault directly go to com_quit via cp_evloop.
+           To avoid potential loop, singnal will be reset in com_quit */
+        signal(SIGSEGV, (void (*)(int))cp_evloop(NULL));
+
         /* If simulation is running, set a breakpoint */ 
         raise (SIGINT);   
         return 0;