[LyX/master] fix lyx2lyx functions

[Juergen Spitzmueller]

commit 01f5efbe13052ac5d0f082a77d888f20b0fdc39e
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sat Aug 17 16:19:10 2024 +0200

    fix lyx2lyx functions
---
 lib/lyx2lyx/lyx_2_5.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/lyx2lyx/lyx_2_5.py b/lib/lyx2lyx/lyx_2_5.py
index 193455227e..c93a3bfc21 100644
--- a/lib/lyx2lyx/lyx_2_5.py
+++ b/lib/lyx2lyx/lyx_2_5.py
@@ -653,7 +653,8 @@ def convert_index_sc(document):
                 k = find_substring(document.body, ec, k, j)
                 if k == -1:
                     break
-                if get_containing_inset(document.body, k)[0] == "ERT":
+                inInset = get_containing_inset(document.body, k)
+                if inInset and inInset[0] == "ERT":
                     k += 1
                     continue
                     
@@ -696,7 +697,8 @@ def revert_index_sc(document):
                 k = find_substring(document.body, ec, k, j)
                 if k == -1:
                     break
-                if get_containing_inset(document.body, k)[0] == "ERT":
+                inInset = get_containing_inset(document.body, k)
+                if inInset and inInset[0] == "ERT":
                     k += 1
                     continue