add faq entry for xapian 1.4.6 regression

diff --git a/faq.mdwn b/faq.mdwn
index 6862685841982e3390179d6b3571bd075f3eaf71..ae705588e3dc279d6721fd1e681b3bdab88e19a3 100644 (file)
--- a/faq.mdwn
+++ b/faq.mdwn
@@ -107,3 +107,24 @@ stop it from propagating again.
 
 See [notmuch-extract-patch](https://github.com/aaptel/notmuch-extract-patch).
 
+## T150-tagging.sh is failing with Xapian 1.4.6
+
+This is (probably) a bug in this point release of Xapian, should be
+fixed in 1.4.7.  Try reverting Xapian commit
+`093999529acc2f86900d91fed0c7f7af301ab94a`, e.g. with the following
+patch.
+
+[[!format text """
+index 80e578b85..a47f14a68 100644
+--- a/xapian-core/backends/glass/glass_postlist.cc
++++ b/xapian-core/backends/glass/glass_postlist.cc
+@@ -759,7 +759,7 @@ GlassPostList::open_nearby_postlist(const std::string & term_,
+     (void)need_pos;
+     if (term_.empty())
+        RETURN(NULL);
+-    if (!this_db.get() || this_db->postlist_table.is_modified())
++    if (!this_db.get() || this_db->postlist_table.is_writable())
+        RETURN(NULL);
+     RETURN(new GlassPostList(this_db, term_, cursor->clone()));
+ }
+"""]]