add the StrContains macro

cmake/templates/NSIS.template.in

@@ -928,6 +928,54 @@ Function HandlePostInstallOptions
 
 FunctionEnd
 
+; StrContains
+; This function does a case sensitive searches for an occurrence of a substring in a string.
+; It returns the substring if it is found.
+; Otherwise it returns null("").
+; Written by kenglish_hi
+; Adapted from StrReplace written by dandaman32
+
+Var STR_HAYSTACK
+Var STR_NEEDLE
+Var STR_CONTAINS_VAR_1
+Var STR_CONTAINS_VAR_2
+Var STR_CONTAINS_VAR_3
+Var STR_CONTAINS_VAR_4
+Var STR_RETURN_VAR
+
+Function StrContains
+  Exch $STR_NEEDLE
+  Exch 1
+  Exch $STR_HAYSTACK
+  ; Uncomment to debug
+  ;MessageBox MB_OK 'STR_NEEDLE = $STR_NEEDLE STR_HAYSTACK = $STR_HAYSTACK '
+    StrCpy $STR_RETURN_VAR ""
+    StrCpy $STR_CONTAINS_VAR_1 -1
+    StrLen $STR_CONTAINS_VAR_2 $STR_NEEDLE
+    StrLen $STR_CONTAINS_VAR_4 $STR_HAYSTACK
+    loop:
+      IntOp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_1 + 1
+      StrCpy $STR_CONTAINS_VAR_3 $STR_HAYSTACK $STR_CONTAINS_VAR_2 $STR_CONTAINS_VAR_1
+      StrCmp $STR_CONTAINS_VAR_3 $STR_NEEDLE found
+      StrCmp $STR_CONTAINS_VAR_1 $STR_CONTAINS_VAR_4 done
+      Goto loop
+    found:
+      StrCpy $STR_RETURN_VAR $STR_NEEDLE
+      Goto done
+    done:
+   Pop $STR_NEEDLE ;Prevent "invalid opcode" errors and keep the
+   Exch $STR_RETURN_VAR
+FunctionEnd
+
+!macro _StrContainsConstructor OUT NEEDLE HAYSTACK
+  Push `${HAYSTACK}`
+  Push `${NEEDLE}`
+  Call StrContains
+  Pop `${OUT}`
+!macroend
+
+!define StrContains '!insertmacro "_StrContainsConstructor"'
+
 ;--------------------------------
 ; determine admin versus local install
 Function un.onInit