[LyX/master] Do not show master's errors if compiling child

[Scott Kostyshak]

commit 8d2b121ef506804fe2c894a61cd4232e87254847
Author: Scott Kostyshak <skost...@lyx.org>
Date:   Sat Apr 7 17:11:33 2018 -0400

    Do not show master's errors if compiling child
    
    If a master document is compiled and has errors, and then a child is
    compiled without error, the errors from the master compilation were
    shown.
    
    The setup of the relevant code is the following:
    
      processingThreadFinished() calls errors().  errors() makes the
      assumption that if it is called, there must have been an error
      somewhere.
    
    The logic of the setup is the following:
    
      processingThreadFinished() knows whether there was an error on
      the most recent preview/export, although it doesn't know whether
      the error is from master or child (i.e. does not know whether the
      user was compiling the child, or whether master-buffer-view was
      called).  Inside error(), if there is no error in the child, it is
      assumed the error is from master.
    
    For the above logic to work, errors() should only be called if there
    was an error.
    
    This commit fixes #11106 and preserves the fix to #7330.
---
 src/frontends/qt4/GuiView.cpp |    5 ++++-
 src/frontends/qt4/GuiView.h   |    3 +++
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index efdd23e..acaa234 100644
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -725,7 +725,10 @@ void GuiView::processingThreadFinished()
                errors("Export");
                return;
        }
-       errors(d.last_export_format);
+       if (status != Buffer::ExportSuccess && status != Buffer::PreviewSuccess 
&&
+           status != Buffer::ExportCancel) {
+               errors(d.last_export_format);
+       }
 }
 
 
diff --git a/src/frontends/qt4/GuiView.h b/src/frontends/qt4/GuiView.h
index 68f1734..3ca4641 100644
--- a/src/frontends/qt4/GuiView.h
+++ b/src/frontends/qt4/GuiView.h
@@ -166,6 +166,9 @@ public:
        /// \name GuiBufferDelegate.
        //@{
        void resetAutosaveTimers();
+       // shows an error list (possibly master's)
+       // even if from_master is false, might show master's error list.
+       // this function should only be called if there was an error (#11106).
        void errors(std::string const &, bool from_master = false);
        void structureChanged();
        void updateTocItem(std::string const &, DocIterator const &);