2007-02-21 Andreia Gaita <avidigal@novell.com>

* PrintingServicesUnix.cs: add checks and try blocks to make sure
things don't blow up if we try to double free anything (not that
we're trying to do anything like that :p )

svn path=/trunk/mcs/; revision=73264

diff --git a/mcs/class/System.Drawing/System.Drawing.Printing/ChangeLog b/mcs/class/System.Drawing/System.Drawing.Printing/ChangeLog
index e1414ac7a3d95c0f4d08258ebe804be76142ba86..3debb595dcda674517227e6bbc5369da7b115159 100644 (file)
--- a/mcs/class/System.Drawing/System.Drawing.Printing/ChangeLog
+++ b/mcs/class/System.Drawing/System.Drawing.Printing/ChangeLog
@@ -1,4 +1,10 @@
-2007-02-20  Andreia Gaita  <avidigal@novell.com>
+2007-02-21  Andreia Gaita  <avidigal@novell.com>
+
+       * PrintingServicesUnix.cs: add checks and try blocks to make sure
+       things don't blow up if we try to double free anything (not that
+       we're trying to do anything like that :p )
+
+2007-02-21  Andreia Gaita  <avidigal@novell.com>
 
        * PrintingServicesUnix.cs: fix a double-free bug
 

diff --git a/mcs/class/System.Drawing/System.Drawing.Printing/PrintingServicesUnix.cs b/mcs/class/System.Drawing/System.Drawing.Printing/PrintingServicesUnix.cs
index 9deb6c95202382c77c75fdb59e44cc19cdffd9bb..abbed3fea1c0603aa0d14c60999086208ca85e8d 100644 (file)
--- a/mcs/class/System.Drawing/System.Drawing.Printing/PrintingServicesUnix.cs
+++ b/mcs/class/System.Drawing/System.Drawing.Printing/PrintingServicesUnix.cs
@@ -110,21 +110,52 @@ namespace System.Drawing.Printing
                /// Open the printer's PPD file
                /// </summary>
                /// <param name="printer">Printer name, returned from cupsGetDests</param>
-               private IntPtr OpenPrinter(string printer)
+               private IntPtr OpenPrinter (string printer)
                {
-                       IntPtr ptr = cupsGetPPD (printer);
-                       string ppd_filename = Marshal.PtrToStringAnsi (ptr);
-                       IntPtr ppd_handle = ppdOpenFile (ppd_filename);
-                       return ppd_handle;
+                       try {
+                               IntPtr ptr = cupsGetPPD (printer);
+                               string ppd_filename = Marshal.PtrToStringAnsi (ptr);
+                               IntPtr ppd_handle = ppdOpenFile (ppd_filename);
+                               return ppd_handle;
+                       }
+                       catch {
+                       }
+                       return IntPtr.Zero;
                }
 
                /// <summary>
                /// Close the printer file
                /// </summary>
                /// <param name="handle">PPD handle</param>
-               private void ClosePrinter(IntPtr handle)
+               private void ClosePrinter (ref IntPtr handle)
                {
-                       ppdClose (handle);
+                       try {
+                               if (handle != IntPtr.Zero)
+                                       ppdClose (handle);
+                       }
+                       finally {
+                               handle = IntPtr.Zero;
+                       }
+               }
+
+               private static int OpenDests (ref IntPtr ptr) {
+                       try {
+                               return cupsGetDests (ref ptr);
+                       }
+                       catch {
+                               ptr = IntPtr.Zero;
+                       }
+                       return 0;
+               }
+
+               private static void CloseDests (ref IntPtr ptr, int count) {
+                       try {
+                               if (ptr != IntPtr.Zero)
+                                       cupsFreeDests (count, ptr);
+                       }
+                       finally {
+                               ptr = IntPtr.Zero;
+                       }
                }
 
                /// <summary>
@@ -160,7 +191,7 @@ namespace System.Drawing.Printing
                                return;
 
                        if (installed_printers.Count == 0)
-                               LoadPrinters();
+                               LoadPrinters ();
 
                        if (((SysPrn.Printer)installed_printers[printer]).Settings != null) {
                                SysPrn.Printer p = (SysPrn.Printer) installed_printers[printer];
@@ -176,7 +207,7 @@ namespace System.Drawing.Printing
                                return;
                        }
 
-                       settings.PrinterCapabilities.Clear();
+                       settings.PrinterCapabilities.Clear ();
 
                        IntPtr dests = IntPtr.Zero, ptr = IntPtr.Zero, ptr_printer, ppd_handle = IntPtr.Zero;
                        string name = String.Empty;
@@ -186,14 +217,17 @@ namespace System.Drawing.Printing
                        NameValueCollection options, paper_names, paper_sources;
 
                        try {
-                               ret = cupsGetDests(ref dests);
-                               cups_dests_size = Marshal.SizeOf(typeof(CUPS_DESTS));
+                               ret = OpenDests (ref dests);
+                               if (ret == 0)
+                                       return;
+
+                               cups_dests_size = Marshal.SizeOf (typeof(CUPS_DESTS));
                                ptr = dests;
                                for (int i = 0; i < ret; i++) {
                                        ptr_printer = (IntPtr) Marshal.ReadInt32 (ptr);
                                        if (Marshal.PtrToStringAnsi (ptr_printer).Equals(printer)) {
                                                name = printer;
-                                               Marshal.FreeHGlobal(ptr_printer);
+                                               Marshal.FreeHGlobal (ptr_printer);
                                                break;
                                        }
                                        Marshal.FreeHGlobal(ptr_printer);
@@ -233,13 +267,12 @@ namespace System.Drawing.Printing
                                settings.supports_color = (ppd.color_device == 0) ? false : true;
                                settings.can_duplex = options["Duplex"] != null;
                        
-                               ClosePrinter(ppd_handle);
+                               ClosePrinter (ref ppd_handle);
                        
                                ((SysPrn.Printer)installed_printers[printer]).Settings = settings;
                        }
                        finally {
-                               if (dests != IntPtr.Zero)
-                                       cupsFreeDests(ret, dests);
+                               CloseDests (ref dests, ret);
                        }
                }
                
@@ -276,8 +309,8 @@ namespace System.Drawing.Printing
                                options = (IntPtr) ((long)options + cups_size);
                        }
                        
-                       LoadOptionList(ppd, "PageSize", paper_names);
-                       LoadOptionList(ppd, "InputSlot", paper_sources);
+                       LoadOptionList (ppd, "PageSize", paper_names);
+                       LoadOptionList (ppd, "InputSlot", paper_sources);
                }
                
                /// <summary>
@@ -439,54 +472,55 @@ namespace System.Drawing.Printing
                        
                        IntPtr dests = IntPtr.Zero, ptr_printers;
                        CUPS_DESTS printer;
-                       int n_printers;
+                       int n_printers = 0;
                        int cups_dests_size = Marshal.SizeOf(typeof(CUPS_DESTS));
                        string name, first, type, status, comment;
                        first = type = status = comment = String.Empty;
                        int state = 0;
                        
-                       n_printers = cupsGetDests (ref dests);
+                       try {
+                               n_printers = OpenDests (ref dests);
 
-                       ptr_printers = dests;
-                       for (int i = 0; i < n_printers; i++) {
-                               printer = (CUPS_DESTS) Marshal.PtrToStructure (ptr_printers, typeof (CUPS_DESTS));
-                               name = Marshal.PtrToStringAnsi (printer.name);
+                               ptr_printers = dests;
+                               for (int i = 0; i < n_printers; i++) {
+                                       printer = (CUPS_DESTS) Marshal.PtrToStructure (ptr_printers, typeof (CUPS_DESTS));
+                                       name = Marshal.PtrToStringAnsi (printer.name);
 
-                               if (printer.is_default == 1)
-                                       default_printer = name;
+                                       if (printer.is_default == 1)
+                                               default_printer = name;
                                
-                               if (first.Equals (String.Empty))
-                                       first = name;
+                                       if (first.Equals (String.Empty))
+                                               first = name;
                        
-                               NameValueCollection options = LoadPrinterOptions(printer.options, printer.num_options);
+                                       NameValueCollection options = LoadPrinterOptions(printer.options, printer.num_options);
                                
-                               if (options["printer-state"] != null)
-                                       state = Int32.Parse(options["printer-state"]);
+                                       if (options["printer-state"] != null)
+                                               state = Int32.Parse(options["printer-state"]);
                                
-                               if (options["printer-comment"] != null)
-                                       comment = options["printer-state"];
-
-                               switch(state)
-                               {
-                                       case 4:
-                                               status = "Printing";
-                                       break;
-                                       case 5:
-                                               status = "Stopped";
-                                       break;
-                                       default:
-                                               status =  "Ready";
-                                       break;
-                               }
+                                       if (options["printer-comment"] != null)
+                                               comment = options["printer-state"];
+
+                                       switch(state) {
+                                               case 4:
+                                                       status = "Printing";
+                                                       break;
+                                               case 5:
+                                                       status = "Stopped";
+                                                       break;
+                                               default:
+                                                       status =  "Ready";
+                                                       break;
+                                       }
                                
-                               installed_printers.Add (name, new SysPrn.Printer (String.Empty, type, status, comment));
+                                       installed_printers.Add (name, new SysPrn.Printer (String.Empty, type, status, comment));
 
-                               ptr_printers = (IntPtr) ((long)ptr_printers + cups_dests_size);
-                       }
+                                       ptr_printers = (IntPtr) ((long)ptr_printers + cups_dests_size);
+                               }
                        
-                       if (dests != IntPtr.Zero)
-                               cupsFreeDests(n_printers, dests);
-                                       
+                       }
+                       finally {
+                               CloseDests (ref dests, n_printers);
+                       }
                        
                        if (default_printer.Equals (String.Empty))
                                default_printer = first;
@@ -511,9 +545,9 @@ namespace System.Drawing.Printing
                                return;
 
                        try {
-                               count = cupsGetDests (ref dests);
+                               count = OpenDests (ref dests);
 
-                               if (dests == IntPtr.Zero)
+                               if (count == 0)
                                        return;
 
                                ptr_printers = dests;
@@ -553,8 +587,7 @@ namespace System.Drawing.Printing
                                }
                        }
                        finally {
-                               if (dests != IntPtr.Zero)
-                                       cupsFreeDests(count, dests);
+                               CloseDests (ref dests, count);
                        }
                }