Fix packdir peeking and potentially poking the reset vector

Detail:
  c/DOSFSops - packdir() was treating its optional 'preserve' parameter as mandatory, leading to peeking (and potentially poking) of null pointers
Admin:
  Tested on Raspberry Pi with high processor vectors


Version 0.91. Tagged as 'DOSFS-0_91'

VersionNum

-/* (0.90)
+/* (0.91)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        0.90
+#define Module_MajorVersion_CMHG        0.91
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                10 Jun 2012
+#define Module_Date_CMHG                14 Jul 2012
 
-#define Module_MajorVersion             "0.90"
-#define Module_Version                  90
+#define Module_MajorVersion             "0.91"
+#define Module_Version                  91
 #define Module_MinorVersion             ""
-#define Module_Date                     "10 Jun 2012"
+#define Module_Date                     "14 Jul 2012"
 
-#define Module_ApplicationDate          "10-Jun-12"
+#define Module_ApplicationDate          "14-Jul-12"
 
 #define Module_ComponentName            "DOSFS"
 #define Module_ComponentPath            "castle/RiscOS/Sources/FileSys/ImageFS/DOSFS"
 
-#define Module_FullVersion              "0.90"
-#define Module_HelpVersion              "0.90 (10 Jun 2012)"
-#define Module_LibraryVersionInfo       "0:90"
+#define Module_FullVersion              "0.91"
+#define Module_HelpVersion              "0.91 (14 Jul 2012)"
+#define Module_LibraryVersionInfo       "0:91"

c/DOSFSops

@@ -1798,7 +1798,7 @@ static int extend_dir(DIR_info **cdir,DOS_direntry **dentry,DOSdisc *ihand,DIR_i
 //Compress' a directory structure by removing deleted entries
 void packdir(DIR_info * cdir, DOS_direntry ** preserve)
 {
- dprintf(("","packdir: cdir = %p, preserve = %p\n",cdir, *preserve));
+ dprintf(("","packdir: cdir = %p, preserve = %p\n",cdir, (preserve?*preserve:NULL)));
  int ip,op;
  int ipend = (cdir->dir_size/32);
  DOS_direntry * dir = (DOS_direntry*)DI_Base(cdir);
@@ -1817,7 +1817,7 @@ void packdir(DIR_info * cdir, DOS_direntry ** preserve)
 //  }
   if((ip != op) && (ip<ipend))
   {//If we need to move entrys in the dir
-   if( (dir+ip) == *preserve) *preserve = (dir+op);
+   if(preserve && ((dir+ip) == *preserve)) *preserve = (dir+op);
    dprintf(("","packdir: ip = %d, op = %d\n",ip,op));
    memmove(dir+op,dir+ip,sizeof(DOS_direntry));
    (dir+ip)->FILE_status = 0xE5;
@@ -1825,7 +1825,7 @@ void packdir(DIR_info * cdir, DOS_direntry ** preserve)
    cdir->lfnp[ip] = NULL;
   }
  }
- dprintf(("","packdir @ exit: cdir = %p, preserve = %p\n",cdir, *preserve));
+ dprintf(("","packdir @ exit: cdir = %p, preserve = %p\n",cdir, (preserve?*preserve:NULL)));
 }