Fix a couple of null/bad pointer dereferences

Detail:
  s/FSControl - faff_boot_option_startup (OS_FSControl 47/48) was acting as if it was given a path variable in r3, but neither of those calls use path variables, leading to aborts in some situations due to random bits of memory being peeked at.
  s/FSUtils - When CopyWildObject performs a single object copy, it wasn't taking into account the fact that the src/dest leafname pointers could be null, potentially causing a crash if high processor vectors are in use.
Since I'm not 100% sure what the correct course of action is (in the case I saw it crash, both src and dest leafnames were null), and there aren't any bugs I know of with file copies using the wrong names, the code now uses the dest leafname if the dest leafname is null.
This sounds wrong, but matches the behaviour of the old code, since byte &00000000 is highly unlikely to contain a '*' character
Admin:
  Tested on BB-xM with high processor vectors


Version 2.77. Tagged as 'FileSwitch-2_77'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "2.76"
-Module_Version          SETA    276
+Module_MajorVersion     SETS    "2.77"
+Module_Version          SETA    277
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "09 Apr 2012"
-Module_ApplicationDate  SETS    "09-Apr-12"
+Module_Date             SETS    "09 Jul 2012"
+Module_ApplicationDate  SETS    "09-Jul-12"
 Module_ComponentName    SETS    "FileSwitch"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/FileSys/FileSwitch"
-Module_FullVersion      SETS    "2.76"
-Module_HelpVersion      SETS    "2.76 (09 Apr 2012)"
+Module_FullVersion      SETS    "2.77"
+Module_HelpVersion      SETS    "2.77 (09 Jul 2012)"
                         END

VersionNum

-/* (2.76)
+/* (2.77)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        2.76
+#define Module_MajorVersion_CMHG        2.77
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                09 Apr 2012
+#define Module_Date_CMHG                09 Jul 2012
 
-#define Module_MajorVersion             "2.76"
-#define Module_Version                  276
+#define Module_MajorVersion             "2.77"
+#define Module_Version                  277
 #define Module_MinorVersion             ""
-#define Module_Date                     "09 Apr 2012"
+#define Module_Date                     "09 Jul 2012"
 
-#define Module_ApplicationDate          "09-Apr-12"
+#define Module_ApplicationDate          "09-Jul-12"
 
 #define Module_ComponentName            "FileSwitch"
 #define Module_ComponentPath            "castle/RiscOS/Sources/FileSys/FileSwitch"
 
-#define Module_FullVersion              "2.76"
-#define Module_HelpVersion              "2.76 (09 Apr 2012)"
-#define Module_LibraryVersionInfo       "2:76"
+#define Module_FullVersion              "2.77"
+#define Module_HelpVersion              "2.77 (09 Jul 2012)"
+#define Module_LibraryVersionInfo       "2:77"

s/FSControl

@@ -2668,9 +2668,8 @@ faff_boot_option_startup
         Entry   "r2-r5"
 
         ; Standard PathMunge sequence
-        MOV     r2, r3
-        MOVS    r3, r4
-        addr    r3, anull, EQ
+        MOV     r2, #0
+        addr    r3, anull
         MOV     r5, #TopPath_WantPartition
         BL      TopPath_DoBusinessForDirectoryRead
         EXIT    VS

s/FSUtils

@@ -561,7 +561,9 @@ CopyWildObject Entry
 
 90
         ; Use src leafname for dst if dst has a '*' leafname
-        LDRB    r14, [r10]
+        ; Use dst leafname if dst leafname is null (sounds silly, but matches old behaviour before null ptr check was added)
+        MOVS    r14, r10
+        LDRNEB  r14, [r10]
         TEQ     r14, #"*"
  [ debugcopy
         BNE     %FT01