[Plplot-cvs] SF.net SVN: plplot:[12931] trunk/drivers/ntk.c

[<ai...@us...>]

Revision: 12931
          http://sourceforge.net/p/plplot/code/12931
Author:   airwin
Date:     2014-01-12 02:14:07 +0000 (Sun, 12 Jan 2014)
Log Message:
-----------
Fix overflowed cmd buffer caused by example 27.

Modified Paths:
--------------
    trunk/drivers/ntk.c

Modified: trunk/drivers/ntk.c
===================================================================
--- trunk/drivers/ntk.c	2014-01-10 20:05:57 UTC (rev 12930)
+++ trunk/drivers/ntk.c	2014-01-12 02:14:07 UTC (rev 12931)
@@ -77,11 +77,15 @@
 static Tk_Window  mainw;          // tk main window
 
 static char       curcolor[80];   // current color in #rrggbb notation
-static char       cmd[10000];     // buffer to build command to interp
-static int        ccanv = 0;      // current canvas number
-static char       base[80];       // name of frame that contains the canvas
-static char       dash[80];       // dash string, as <mark space>*
 
+// 12000 is large enough to satisfy example 27 needs without
+// erroring out in plD_polyline_ntk.  Quadruple that to be conservative.
+#define PLPLOT_NTK_CMD_SIZE    48000
+static char cmd[PLPLOT_NTK_CMD_SIZE]; // buffer to build command to interp
+static int  ccanv = 0;                // current canvas number
+static char base[80];                 // name of frame that contains the canvas
+static char dash[80];                 // dash string, as <mark space>*
+
 // line buffering
 #define NPTS    1000
 static short xold = -1, yold = -1; // last point of last 2 points line
@@ -103,7 +107,7 @@
 static void
 tk_cmd( const char *gcmd )
 {
-    static char scmd[10000];
+    static char scmd[PLPLOT_NTK_CMD_SIZE];
 
     if ( local )
         Tcl_Eval( interp, gcmd );
@@ -351,8 +355,14 @@
     // there must exist a way to code this using the tk C API
     j = sprintf( cmd, "$plf.f2.c%d create line ", ccanv );
     for ( i = 0; i < npts; i++ )
+    {
+        // To be completely safe, assume 5 characters to the left of the
+        // decimal point ==> 2*(5+3) characters written per sprintf
+        // call.
+        if ( ( j + 16 ) > PLPLOT_NTK_CMD_SIZE )
+            plexit( "plD_polyline_ntk: too many x, y values to hold in static cmd array" );
         j += sprintf( &cmd[j], "%.1f %.1f ", xa[i] / scale, ymax - ya[i] / scale );
-
+    }
     j += sprintf( &cmd[j], " -fill %s", curcolor );
     if ( dash[0] == '-' )
         j += sprintf( &cmd[j], " %s", dash );
@@ -526,7 +536,7 @@
     case PLESC_FILL:
         if ( pls->patt != 0 )
         {
-            // this is a hack! The real solution is in the if(0) bellow
+            // this is a hack! The real solution is in the if(0) below
             pls->xpmm *= scale;
             pls->ypmm *= scale;
             plfill_soft( pls->dev_x, pls->dev_y, pls->dev_npts );

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