とりあえずいけたぽい

lltexteditor.cpp.patch

--- a/indra/llui/lltexteditor.cpp
+++ b/indra/llui/lltexteditor.cpp
@@ -2832,12 +2832,13 @@ BOOL LLTextEditor::getPreeditLocation(S32 query_offset, LLCoordGL *coord, LLRect

     const LLWString textString(getWText());
        const llwchar * const text = textString.c_str();
-       const S32 line_height = mFont->getLineHeight();
+       const line_info& line = mLineInfoList[current_line];
+       LLRect text_rect(line.mRect);

        if (coord)
        {
                const S32 query_x = mVisibleTextRect.mLeft + mFont->getWidth(text, current_line_start, query - current_line_start);
-               const S32 query_y = mVisibleTextRect.mTop - (current_line - first_visible_line) * line_height - line_height / 2;
+               const S32 query_y = (text_rect.mTop + text_rect.mBottom) / 2.0;
                S32 query_screen_x, query_screen_y;
                localPointToScreen(query_x, query_y, &query_screen_x, &query_screen_y);
                LLUI::screenPointToGL(query_screen_x, query_screen_y, &coord->mX, &coord->mY);
@@ -2861,8 +2862,8 @@ BOOL LLTextEditor::getPreeditLocation(S32 query_offset, LLCoordGL *coord, LLRect
                        preedit_right += mFont->getWidth(text, current_line_start, current_line_end - current_line_start);
                }

-               const S32 preedit_top = mVisibleTextRect.mTop - (current_line - first_visible_line) * line_height;
-               const S32 preedit_bottom = preedit_top - line_height;
+               const S32 preedit_top = text_rect.mTop;
+               const S32 preedit_bottom = text_rect.mBottom;

                const LLRect preedit_rect_local(preedit_left, preedit_top, preedit_right, preedit_bottom);
                LLRect preedit_rect_screen;