[LyX/master] Don't sort the bibfiles cache.

[Richard Kimberly Heck]

commit 6b095e2b7107110bec593edd02bbdcf25adae76a
Author: Richard Kimberly Heck <rikih...@lyx.org>
Date:   Wed Apr 25 13:40:37 2018 -0400

    Don't sort the bibfiles cache.
    
    This causes problems with biblatex. Instead, we sort the old and
    new lists and then compare them.
---
 src/Buffer.cpp |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index ee27f8f..74d5ac8 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -4791,9 +4791,13 @@ void Buffer::updateBuffer(UpdateScope scope, UpdateType 
utype) const
                return;
 
        // if the bibfiles changed, the cache of bibinfo is invalid
-       sort(d->bibfiles_cache_.begin(), d->bibfiles_cache_.end());
-       // the old one should already be sorted
-       if (old_bibfiles != d->bibfiles_cache_) {
+       FileNamePairList new_bibfiles = d->bibfiles_cache_;
+       // this is a trick to determine whether the two vectors have
+       // the same elements.
+       sort(new_bibfiles.begin(), new_bibfiles.end());
+       sort(old_bibfiles.begin(), old_bibfiles.end());
+       if (old_bibfiles != new_bibfiles) {
+               LYXERR(Debug::FILES, "Reloading bibinfo cache.");
                invalidateBibinfoCache();
                reloadBibInfoCache();
                // We relied upon the bibinfo cache when recalculating labels. 
But that
@@ -4810,8 +4814,11 @@ void Buffer::updateBuffer(UpdateScope scope, UpdateType 
utype) const
                // updateMacros();
                setChangesPresent(false);
                updateBuffer(parit, utype);
+               // this will already have been done by reloadBibInfoCache();
+               // d->bibinfo_cache_valid_ = true;
        }
        else {
+               LYXERR(Debug::FILES, "Bibfiles unchanged.");
                // this is also set to true on the other path, by 
reloadBibInfoCache.
                d->bibinfo_cache_valid_ = true;
        }