Windows Accessibility: Fixed backspace character reporting under NVDA

The change introduced in 92f350e617 led to
a regression in the MoveEndpointByUnit function. In this case, a
backward movement by a single character *should* move the endpoint as
long as it remains within the text range.

The issue addressed by the faulty commit is better fixed by
special-casing the 'character' unit case in the ExpandToEnclosingUnit
function.

modules/juce_gui_basics/native/accessibility/juce_AccessibilityTextHelpers.h

@@ -49,13 +49,12 @@ namespace AccessibilityTextHelpers
     {
         const auto numCharacters = textInterface.getTotalNumCharacters();
         const auto isForwards = (direction == Direction::forwards);
-
-        const auto offsetWithDirecton = [isForwards] (int input) { return isForwards ? input : -input; };
+        const auto offsetWithDirection = [isForwards] (auto num) { return isForwards ? num : -num; };
 
         switch (boundary)
         {
             case BoundaryType::character:
-                return jlimit (0, numCharacters, isForwards ? currentPosition + 1 : currentPosition);
+                return jlimit (0, numCharacters, currentPosition + offsetWithDirection (1));
 
             case BoundaryType::word:
             case BoundaryType::line:
@@ -96,7 +95,7 @@ namespace AccessibilityTextHelpers
                 auto tokens = (boundary == BoundaryType::line ? StringArray::fromLines (text)
                                                               : StringArray::fromTokens (text, false));
 
-                return currentPosition + offsetWithDirecton (tokens[0].length());
+                return currentPosition + offsetWithDirection (tokens[0].length());
             }
 
             case BoundaryType::document:

modules/juce_gui_basics/native/accessibility/juce_win32_UIATextProvider.h

@@ -248,7 +248,9 @@ private:
             {
                 const auto boundaryType = getBoundaryType (unit);
 
-                const auto start = AccessibilityTextHelpers::findTextBoundary (*textInterface,
+                const auto start = unit == ComTypes::TextUnit::TextUnit_Character
+                                 ? selectionRange.getStart()
+                                 : AccessibilityTextHelpers::findTextBoundary (*textInterface,
                                                                                selectionRange.getStart(),
                                                                                boundaryType,
                                                                                AccessibilityTextHelpers::Direction::backwards);