Prevent a crash when destroying insets whose Buffers have been closed.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@25150 a592a061-630c-0410-9148-cb99ea01b6c8

src/insets/Inset.cpp

@@ -18,6 +18,7 @@
 
 #include "buffer_funcs.h"
 #include "Buffer.h"
+#include "BufferList.h"
 #include "BufferParams.h"
 #include "BufferView.h"
 #include "CoordCache.h"
@@ -148,6 +149,12 @@ Buffer const & Inset::buffer() const
 }
 
 
+bool Inset::isBufferValid() const
+{
+	return theBufferList().isLoaded(buffer_);
+}
+
+
 docstring Inset::name() const
 {
 	return from_ascii("unknown");

src/insets/Inset.h

@@ -103,6 +103,9 @@ public:
 	/// retrieve associated Buffer
 	virtual Buffer & buffer();
 	virtual Buffer const & buffer() const;
+	/// This checks whether the Buffer * actually points to an open 
+	/// Buffer. It might not if that Buffer has been closed.
+	bool isBufferValid() const;
 
 	/// initialize view for this inset.
 	/**

src/insets/InsetBibitem.cpp

@@ -57,7 +57,7 @@ InsetBibitem::InsetBibitem(Buffer const & buf, InsetCommandParams const & p)
 
 InsetBibitem::~InsetBibitem()
 {
-	if (buffer_)
+	if (isBufferValid())
 		buffer_->invalidateBibinfoCache();
 }
 

src/insets/InsetBibtex.cpp

@@ -59,7 +59,7 @@ InsetBibtex::InsetBibtex(Buffer const & buf, InsetCommandParams const & p)
 
 InsetBibtex::~InsetBibtex()
 {
-	if (buffer_)
+	if (isBufferValid())
 		buffer_->invalidateBibinfoCache();
 }