Fix abort error with ^K and ^X in writable icons

Check there is actually a selection present in the window before cutting/deleting any text.

Version 5.74. Tagged as 'Wimp-5_74'

VersionASM

@@ -9,12 +9,12 @@
                         GBLS    Module_ApplicationDate
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
-Module_MajorVersion     SETS    "5.73"
-Module_Version          SETA    573
+Module_MajorVersion     SETS    "5.74"
+Module_Version          SETA    574
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "02 May 2020"
-Module_ApplicationDate  SETS    "02-May-20"
+Module_Date             SETS    "11 May 2020"
+Module_ApplicationDate  SETS    "11-May-20"
 Module_ComponentName    SETS    "Wimp"
-Module_FullVersion      SETS    "5.73"
-Module_HelpVersion      SETS    "5.73 (02 May 2020)"
+Module_FullVersion      SETS    "5.74"
+Module_HelpVersion      SETS    "5.74 (11 May 2020)"
                         END

VersionNum

-/* (5.73)
+/* (5.74)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  *
  */
-#define Module_MajorVersion_CMHG        5.73
+#define Module_MajorVersion_CMHG        5.74
 #define Module_MinorVersion_CMHG
-#define Module_Date_CMHG                02 May 2020
+#define Module_Date_CMHG                11 May 2020
 
-#define Module_MajorVersion             "5.73"
-#define Module_Version                  573
+#define Module_MajorVersion             "5.74"
+#define Module_Version                  574
 #define Module_MinorVersion             ""
-#define Module_Date                     "02 May 2020"
+#define Module_Date                     "11 May 2020"
 
-#define Module_ApplicationDate          "02-May-20"
+#define Module_ApplicationDate          "11-May-20"
 
 #define Module_ComponentName            "Wimp"
 
-#define Module_FullVersion              "5.73"
-#define Module_HelpVersion              "5.73 (02 May 2020)"
-#define Module_LibraryVersionInfo       "5:73"
+#define Module_FullVersion              "5.74"
+#define Module_HelpVersion              "5.74 (11 May 2020)"
+#define Module_LibraryVersionInfo       "5:74"

s/Wimp05

@@ -3965,8 +3965,8 @@ clipboard_possible_wcut
         Pull    "R7,PC",EQ              ; no clipboard function for this icon
 
         LDR     R7,[handle,#w_seldata+wselicon]
-        TEQ     R7,R1
-        Pull    "R7,PC",NE              ; no selection present for this icon
+        CMP     R7,#nullptr
+        Pull    "R7,PC",EQ              ; no selection present
 
         LDR     R7,[handle,#w_seldata+wsellowindex]
         LDR     R14,[handle,#w_seldata+wselhighindex]
@@ -3979,6 +3979,13 @@ clipboard_wcut
         ; request cut of data from icon to clipboard
         BL      clipboard_check_disabled
         BEQ     passbacktouser
+
+        Push    "R7"
+        LDR     R7,[handle,#w_seldata+wselicon]
+        CMP     R7,#nullptr
+        Pull    "R7"
+        BEQ     exitprocess             ; no selection present for this icon
+
         BL      clipboard_setupdata
         Push    "R0"
         BL      clipboard_check_password
@@ -4003,6 +4010,13 @@ clipboard_wcut
 clipboard_wdelete
         BL      clipboard_check_disabled
         BEQ     passbacktouser
+
+        Push    "R7"
+        LDR     R7,[handle,#w_seldata+wselicon]
+        CMP     R7,#nullptr
+        Pull    "R7"
+        BEQ     exitprocess             ; no selection present
+
         BL      clipboard_setupdata
         BL      clipboard_wdelete_perform
         B       exitprocess