[GRASS-dev] v.digit segfault with tcltk 8.3 -- solution?

[Hamish]

Hi,

WRT the "new" v.digit segfaulting on startup (Tcl/Tk 8.3; Debian/Sarge;
i686), I have traced it to vector/v.digit/driver.c in the get_window()
fn:

 Tcl_Eval(Toolbox, "list 0 [winfo height .screen.canvas] 0 [winfo width .screen.canvas]");


even this breaks it:
    Tcl_Eval(Toolbox, "list [winfo height .screen.canvas]");
or just
    Tcl_Eval(Toolbox, "list [expr 1+1]");
or
    Tcl_Eval(Toolbox, "concat [expr 1]");

while this works:
    Tcl_Eval(Toolbox, "winfo height .screen.canvas");


note that a few lines later it calls this, without error:
    Tcl_Eval(Toolbox, "list 0 [.screen.canvas cget -height] 0 [.screen.canvas cget -width]");


no idea why nesting [commands] matters, but without [] it works & the
attached patch gets v.digit working again for tcltk 8.3.

ok for CVS?


Hamish
-------------- next part --------------
Index: vector/v.digit/driver.c
===================================================================
RCS file: /home/grass/grassrepository/grass6/vector/v.digit/driver.c,v
retrieving revision 1.8
diff -u -r1.8 driver.c
--- vector/v.digit/driver.c	24 Feb 2007 21:38:37 -0000	1.8
+++ vector/v.digit/driver.c	10 May 2007 09:16:30 -0000
@@ -55,8 +55,13 @@
 
 static void get_window(int *t, int *b, int *l, int *r)
 {
-    Tcl_Eval(Toolbox, "list 0 [winfo height .screen.canvas] 0 [winfo width .screen.canvas]");
-    sscanf(Toolbox->result, "%d %d %d %d", t, b, l, r);
+    *t = *l = 0;
+
+    Tcl_Eval(Toolbox, "winfo height .screen.canvas");
+    sscanf(Toolbox->result, "%d", b);
+
+    Tcl_Eval(Toolbox, "winfo width .screen.canvas");
+    sscanf(Toolbox->result, "%d", r);
 
     if (*b > 1 || *r > 1)
 	    return;
@@ -96,7 +101,7 @@
     
     if (Tcl_Eval(Toolbox, "create_screen") != TCL_OK)
 	G_warning("create_screen: %s", Toolbox->result);
-    
+
 
     setup();