[LyX/2.3.x] Do not add deleted text to inset button label.

[Juergen Spitzmueller]

commit d088f7f03f10bf7a51c807e9b0a3172449c15a01
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Sun Oct 22 19:08:10 2017 +0200

    Do not add deleted text to inset button label.
    
    Fixes: #10775
    (cherry picked from commit 70b0df85c80120e0a0eeaa9e3fec721d91d53849)
---
 src/insets/InsetCollapsible.cpp |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/src/insets/InsetCollapsible.cpp b/src/insets/InsetCollapsible.cpp
index 11c9e2a..c429c51 100644
--- a/src/insets/InsetCollapsible.cpp
+++ b/src/insets/InsetCollapsible.cpp
@@ -423,6 +423,8 @@ docstring const InsetCollapsible::getNewLabel(docstring 
const & l) const
        pos_type i = 0;
        pos_type j = 0;
        for (; i < n && j < p_siz; ++j) {
+               if (paragraphs().begin()->isDeleted(j))
+                       continue;
                if (paragraphs().begin()->isInset(j)) {
                        if (!paragraphs().begin()->getInset(j)->isChar())
                                continue;