Handle encoding error in layout file parsing more gracefully

Issue a warning about non-decodable files, but do not break
completely.

Addresses #11736

(cherry picked from commit c4da8d38c9)

lib/configure.py

@@ -1417,6 +1417,7 @@ def checkLatexConfig(check_config, bool_docbook):
         classname = file.split(os.sep)[-1].split('.')[0]
         decline = ""
         catline = ""
+        try:
             for line in open(file, 'r', encoding='utf8').readlines():
                 if not empty.match(line) and line[0] != '#'[0]:
                     if decline == "":
@@ -1437,6 +1438,14 @@ def checkLatexConfig(check_config, bool_docbook):
                 break
             if nodeclaration:
                 continue
+        except UnicodeDecodeError:
+            logger.warning("**************************************************\n"
+                           "Layout file '%s'\n"
+                           "cannot be decoded in utf-8.\n"
+                           "Please check if the file has the correct encoding.\n"
+                           "Skipping this file!\n"
+                           "**************************************************" % file)
+            continue
     testclasses.sort()
     cl = open('chklayouts.tex', 'w', encoding='utf8')
     for line in testclasses:

status.23x

@@ -53,6 +53,7 @@ What's new
 
 - Correctly strike out deleted text after deleted display math (bug 11716).
 
+
 * USER INTERFACE
 
 - Fix backspace deletion of selected items with change tracking (bug 11630).
@@ -84,11 +85,12 @@ What's new
 
 
 
-
 * ADVANCED FIND AND REPLACE
 
 
 
-
 * BUILD/INSTALLATION
 
+- Do not break configuration if a layout file is not decodable. Rather than that, 
+  issue a warning and skip that file (bug 11736).
+