[LyX/2.3.x] Missing backports in the context of #9158

[Juergen Spitzmueller]

commit 67495a71d14b66c62f2927ad0da4070d17eeef19
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Mon Oct 15 08:04:31 2018 +0200

    Missing backports in the context of #9158
    
    This fixes the remaining regressions in stable with citation
---
 src/Buffer.cpp             |    5 +++++
 src/insets/InsetBibtex.cpp |    7 +++++++
 src/insets/InsetBibtex.h   |    2 ++
 3 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index fce5b4c..1196874 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -4808,6 +4808,11 @@ void Buffer::updateBuffer(UpdateScope scope, UpdateType 
utype) const
        if (master == this && !d->ignore_parent) {
                textclass.counters().reset(from_ascii("bibitem"));
                reloadBibInfoCache();
+               // we will re-read this cache as we go through, but we need
+               // to know whether it's changed to know whether we need to
+               // update the bibinfo cache.
+               old_bibfiles = d->bibfiles_cache_;
+               d->bibfiles_cache_.clear();
        }
 
        // keep the buffers to be children in this set. If the call from the
diff --git a/src/insets/InsetBibtex.cpp b/src/insets/InsetBibtex.cpp
index 9724e95..e4c7f30 100644
--- a/src/insets/InsetBibtex.cpp
+++ b/src/insets/InsetBibtex.cpp
@@ -879,6 +879,13 @@ void InsetBibtex::validate(LaTeXFeatures & features) const
 }
 
 
+void InsetBibtex::updateBuffer(ParIterator const &, UpdateType)
+{
+       buffer().registerBibfiles(getBibFiles());
+}
+
+
+
 docstring InsetBibtex::getRefLabel() const 
 { 
        if (buffer().masterParams().documentClass().hasLaTeXLayout("chapter")) 
diff --git a/src/insets/InsetBibtex.h b/src/insets/InsetBibtex.h
index bcad1a6..c8a6592 100644
--- a/src/insets/InsetBibtex.h
+++ b/src/insets/InsetBibtex.h
@@ -57,6 +57,8 @@ public:
        int plaintext(odocstringstream & ods, OutputParams const & op,
                      size_t max_length = INT_MAX) const;
        ///
+       void updateBuffer(ParIterator const &, UpdateType);
+       ///
        void addToToc(DocIterator const & di, bool output_active,
                                  UpdateType utype, TocBackend & backend) const;
        ///