Gate the recache of currentmode

The operations at module init and at Service_PreReset are both implicitly pre desktop, however it is valid to have Service_ModeFileChanged while in the desktop (for example, if selecting a different MDF from !ScrnSetup).
Gate the one hanging off Service_ModeFileChanged to only act when there are no tasks active (ie. outside the Wimp).
Fixes problem reported https://www.riscosopen.org/forum/forums/4/topics/9206 with NetSurf redraw.

Version 5.58. Tagged as 'Wimp-5_58'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "5.57"
-Module_Version          SETA    557
+Module_MajorVersion     SETS    "5.58"
+Module_Version          SETA    558
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "08 Apr 2017"
-Module_ApplicationDate  SETS    "08-Apr-17"
+Module_Date             SETS    "11 Apr 2017"
+Module_ApplicationDate  SETS    "11-Apr-17"
 Module_ComponentName    SETS    "Wimp"
 Module_ComponentPath    SETS    "castle/RiscOS/Sources/Desktop/Wimp"
-Module_FullVersion      SETS    "5.57"
-Module_HelpVersion      SETS    "5.57 (08 Apr 2017)"
+Module_FullVersion      SETS    "5.58"
+Module_HelpVersion      SETS    "5.58 (11 Apr 2017)"
                         END

VersionNum

-/* (5.57)
+/* (5.58)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        5.57
+#define Module_MajorVersion_CMHG        5.58
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                08 Apr 2017
+#define Module_Date_CMHG                11 Apr 2017
 
-#define Module_MajorVersion             "5.57"
-#define Module_Version                  557
+#define Module_MajorVersion             "5.58"
+#define Module_Version                  558
 #define Module_MinorVersion             ""
-#define Module_Date                     "08 Apr 2017"
+#define Module_Date                     "11 Apr 2017"
 
-#define Module_ApplicationDate          "08-Apr-17"
+#define Module_ApplicationDate          "11-Apr-17"
 
 #define Module_ComponentName            "Wimp"
 #define Module_ComponentPath            "castle/RiscOS/Sources/Desktop/Wimp"
 
-#define Module_FullVersion              "5.57"
-#define Module_HelpVersion              "5.57 (08 Apr 2017)"
-#define Module_LibraryVersionInfo       "5:57"
+#define Module_FullVersion              "5.58"
+#define Module_HelpVersion              "5.58 (11 Apr 2017)"
+#define Module_LibraryVersionInfo       "5:58"

s/Wimp01

@@ -4146,7 +4146,7 @@ Service2
         TEQ     R1,#Service_ModeChanging
         BEQ     releasewrchvpremodechange
         TEQ     R1, #Service_ModeFileChanged
-        BEQ     read_current_configd_mode
+        BEQ     servicemodefilechanged
         TEQ     R1,#Service_Reset
         MOVNE   PC,LR
 
@@ -4193,6 +4193,15 @@ serviceresourcefsstarting
         MOV     PC,R2                   ; R2 -> address to call
         Pull    "R0,PC"
 
+; A new MDF was loaded, this might have improved the kernel's idea
+; of what the configured 'auto' mode achievable is, recache currentmode
+
+servicemodefilechanged
+        Push    "LR"
+        LDR     LR,taskcount
+        TEQ     LR,#0                   ; but only if we're outside the desktop
+        BLEQ    read_current_configd_mode
+        Pull    "PC"
 
 ; try to locate ROM sprite area - if not found, refuse to start up!
 ; this MUST be in Resources:, as we need to use it directly

s/Wimp02

@@ -1825,7 +1825,7 @@ vduin_scrsize
         DCD     VduExt_TotalScreenSize
         DCD     -1
 
-; note_configd_mode
+; read_current_configd_mode
 ; look at the currently configured mode
 
 read_current_configd_mode ROUT