riched20: Fix-up the scrollbar visibility in the host.

dlls/riched20/paint.c

@@ -1057,7 +1057,6 @@ static void set_scroll_range_pos( ITextHost *host, INT bar, SCROLLINFO *info, BO
 
 void ME_ScrollAbs(ME_TextEditor *editor, int x, int y)
 {
-  BOOL old_vis, new_vis;
   int scrollX = 0, scrollY = 0;
 
   if (editor->horz_si.nPos != x) {
@@ -1076,33 +1075,14 @@ void ME_ScrollAbs(ME_TextEditor *editor, int x, int y)
     set_scroll_range_pos( editor->texthost, SB_VERT, &editor->vert_si, FALSE );
   }
 
-  if (abs(scrollX) > editor->sizeWindow.cx ||
-      abs(scrollY) > editor->sizeWindow.cy)
+  if (abs(scrollX) > editor->sizeWindow.cx || abs(scrollY) > editor->sizeWindow.cy)
     ITextHost_TxInvalidateRect(editor->texthost, NULL, TRUE);
   else
     ITextHost_TxScrollWindowEx(editor->texthost, scrollX, scrollY,
                                &editor->rcFormat, &editor->rcFormat,
                                NULL, NULL, SW_INVALIDATE);
-  ME_Repaint(editor);
-
-  if (editor->hWnd)
-  {
-    LONG winStyle = GetWindowLongW(editor->hWnd, GWL_STYLE);
-    if (editor->scrollbars & WS_HSCROLL)
-    {
-      old_vis = winStyle & WS_HSCROLL;
-      new_vis = editor->horz_sb_enabled || editor->scrollbars & ES_DISABLENOSCROLL;
-      if (!old_vis ^ !new_vis) ITextHost_TxShowScrollBar( editor->texthost, SB_HORZ, new_vis );
-    }
-
-    if (editor->scrollbars & WS_VSCROLL)
-    {
-      old_vis = winStyle & WS_VSCROLL;
-      new_vis = editor->vert_sb_enabled || editor->scrollbars & ES_DISABLENOSCROLL;
-      if (!old_vis ^ !new_vis) ITextHost_TxShowScrollBar( editor->texthost, SB_VERT, new_vis );
-    }
-  }
   ME_UpdateScrollBar(editor);
+  ME_Repaint(editor);
 }
 
 void ME_HScrollAbs(ME_TextEditor *editor, int x)

dlls/riched20/txthost.c

@@ -222,6 +222,24 @@ DEFINE_THISCALL_WRAPPER(ITextHostImpl_TxSetScrollPos,16)
 DECLSPEC_HIDDEN BOOL __thiscall ITextHostImpl_TxSetScrollPos( ITextHost *iface, INT bar, INT pos, BOOL redraw )
 {
     struct host *host = impl_from_ITextHost( iface );
+    DWORD style = GetWindowLongW( host->window, GWL_STYLE );
+    DWORD mask = (bar == SB_HORZ) ? WS_HSCROLL : WS_VSCROLL;
+    BOOL show = TRUE, shown = style & mask;
+
+    if (bar != SB_HORZ && bar != SB_VERT)
+    {
+        FIXME( "Unexpected bar %d\n", bar );
+        return FALSE;
+    }
+
+    /* If the application has adjusted the scrollbar's visibility it is reset */
+    if (!(host->scrollbars & ES_DISABLENOSCROLL))
+    {
+        if (bar == SB_HORZ) ITextServices_TxGetHScroll( host->text_srv, NULL, NULL, NULL, NULL, &show );
+        else ITextServices_TxGetVScroll( host->text_srv, NULL, NULL, NULL, NULL, &show );
+    }
+
+    if (!show ^ !shown) ShowScrollBar( host->window, bar, show );
     return SetScrollPos( host->window, bar, pos, redraw ) != 0;
 }