Merge "Remove nbsp and similar characters from section IDs"

diff --combined RELEASE-NOTES-1.31
index 08e6109,3688163..9a4c74c
--- 1/RELEASE-NOTES-1.31
--- 2/RELEASE-NOTES-1.31
+++ b/RELEASE-NOTES-1.31
@@@ -41,6 -41,7 +41,7 @@@ production
  * …
  
  === Bug fixes in 1.31 ===
+ * (T90902) Non-breaking space in header ID breaks anchor
  * …
  
  === Action API changes in 1.31 ===
@@@ -92,9 -93,8 +93,9 @@@ changes to languages because of Phabric
    * Revision::selectArchiveFields() → Revision::getArchiveQueryInfo()
    * User::selectFields() → User::getQueryInfo()
    * WikiPage::selectFields() → WikiPage::getQueryInfo()
 -* Due to significant refactoring, method ContribsPager::getUserCond() that had
 -  no access restriction has been removed.
 +  * Due to significant refactoring, method ContribsPager::getUserCond() that had
 +    no access restriction has been removed.
 +  * Revision::setUserIdAndName() was deprecated.
  
  == Compatibility ==
  MediaWiki 1.31 requires PHP 5.5.9 or later. There is experimental support for