Fix TopPath_DoBusinessToPath leaking memory on error

Detail:
  s/TopPath - Code which attempted to free the cleaned up user's path incorrectly assumed that it could find the string via the stacked R0. However stacked regs R0-R6 get updated with the found objects details, so we need to store a copy of the users R0 elsewhere and free the string via that instead.
Admin:
  Fixes OS_FSControl 37 (and other operations?) filling the system heap if given paths which will generate errors (e.g. if drive empty/missing)


Version 2.76. Tagged as 'FileSwitch-2_76'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "2.75"
-Module_Version          SETA    275
+Module_MajorVersion     SETS    "2.76"
+Module_Version          SETA    276
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "20 Feb 2012"
-Module_ApplicationDate  SETS    "20-Feb-12"
+Module_Date             SETS    "09 Apr 2012"
+Module_ApplicationDate  SETS    "09-Apr-12"
 Module_ComponentName    SETS    "FileSwitch"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/FileSys/FileSwitch"
-Module_FullVersion      SETS    "2.75"
-Module_HelpVersion      SETS    "2.75 (20 Feb 2012)"
+Module_FullVersion      SETS    "2.76"
+Module_HelpVersion      SETS    "2.76 (09 Apr 2012)"
                         END

VersionNum

-/* (2.75)
+/* (2.76)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        2.75
+#define Module_MajorVersion_CMHG        2.76
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                20 Feb 2012
+#define Module_Date_CMHG                09 Apr 2012
 
-#define Module_MajorVersion             "2.75"
-#define Module_Version                  275
+#define Module_MajorVersion             "2.76"
+#define Module_Version                  276
 #define Module_MinorVersion             ""
-#define Module_Date                     "20 Feb 2012"
+#define Module_Date                     "09 Apr 2012"
 
-#define Module_ApplicationDate          "20-Feb-12"
+#define Module_ApplicationDate          "09-Apr-12"
 
 #define Module_ComponentName            "FileSwitch"
 #define Module_ComponentPath            "castle/RiscOS/Sources/FileSys/FileSwitch"
 
-#define Module_FullVersion              "2.75"
-#define Module_HelpVersion              "2.75 (20 Feb 2012)"
-#define Module_LibraryVersionInfo       "2:75"
+#define Module_FullVersion              "2.76"
+#define Module_HelpVersion              "2.76 (09 Apr 2012)"
+#define Module_LibraryVersionInfo       "2:76"

s/TopPath

@@ -86,6 +86,7 @@ TopPath_WantPartition   *       1:SHL:7
         ^       0, sp
 FSPath_Context  #       4
 Appendment      #       4       ; Path tail to append to prefix(es) from path variable(s)
+CleanedUpPath   #       4       ; Copy of R0 on entry
 TopPath_ContextSize #   0
 
 TopPath_DoBusinessToPath Entry "r7"
@@ -97,6 +98,7 @@ TopPath_DoBusinessToPathFSPrefix Entry "r0-r9",:INDEX:TopPath_ContextSize
         DREG    r6, "DoBusinessToPath r6 in is "
  ]
         MOV     r7, r4
+        STR     r0, CleanedUpPath
 
         ; Copy path from user space to my space, cleaning it up as we go
         BL      TopPath_CopyCleanTransAndPoliceWithError
@@ -476,7 +478,7 @@ TopPath_DoBusinessToPathFSPrefix Entry "r0-r9",:INDEX:TopPath_ContextSize
         MOV     r1, r0
 
         ; Junk the cleaned-up path
-        LDR     r0, [sp, #Proc_LocalStack + 0*4]
+        LDR     r0, CleanedUpPath
         BL      SFreeLinkedString
  [ debugpath
         LDR     r0, globalerror