From 87d291ee237cd24419ced6237b52518a53a4f474 Mon Sep 17 00:00:00 2001
From: Jean-Marc Lasgouttes <lasgouttes@lyx.org>
Date: Wed, 13 Dec 2017 10:38:47 +0100
Subject: [PATCH] Handle properly undo groups in embedded work areas

When a buffer is in an embedded work area (adv. find&replace), it is
not found by BufferList:::exists(), and therefore the undo group
created in GuiApplication::dispatch and in the handling of
LFUN_COMMAND_SEQUENCE will not be closed.. Crashes can ensue, as
described in Ubuntu bug:
https://bugs.launchpad.net/bugs/1737429

The solution is to introduce BufferList::isInternal and act on it.

Fixes bug #10847.

(cherry picked from commit 8b107f0490e61b4390e925f08d21661ef50d6f49)
---
 src/BufferList.cpp                   | 12 +++++++++++-
 src/BufferList.h                     |  3 +++
 src/Undo.cpp                         |  6 ++++--
 src/frontends/qt4/GuiApplication.cpp |  4 ++--
 4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/BufferList.cpp b/src/BufferList.cpp
index a61b0bfd80..5e83c7b63e 100644
--- a/src/BufferList.cpp
+++ b/src/BufferList.cpp
@@ -269,7 +269,7 @@ bool BufferList::exists(FileName const & fname) const
 }
 
 
- bool BufferList::isLoaded(Buffer const * b) const
+bool BufferList::isLoaded(Buffer const * b) const
 {
 	if (!b)
 		return false;
@@ -279,6 +279,16 @@ bool BufferList::exists(FileName const & fname) const
 }
 
 
+bool BufferList::isInternal(Buffer const * b) const
+{
+	if (!b)
+		return false;
+	BufferStorage::const_iterator cit =
+		find(binternal.begin(), binternal.end(), b);
+	return cit != binternal.end();
+}
+
+
 bool BufferList::isOthersChild(Buffer * parent, Buffer * child)
 {
 	LASSERT(parent, return false);
diff --git a/src/BufferList.h b/src/BufferList.h
index 01698af4bb..ca55abe8c9 100644
--- a/src/BufferList.h
+++ b/src/BufferList.h
@@ -84,6 +84,9 @@ public:
 	/// returns true if the buffer is loaded
 	bool isLoaded(Buffer const * b) const;
 
+	/// returns true if the buffer is known as internal buffer
+	bool isInternal(Buffer const * b) const;
+
 	/// \return index of named buffer in buffer list
 	int bufferNum(support::FileName const & name) const;
 
diff --git a/src/Undo.cpp b/src/Undo.cpp
index a479728ebd..f7ee48205f 100644
--- a/src/Undo.cpp
+++ b/src/Undo.cpp
@@ -562,7 +562,8 @@ void Undo::beginUndoGroup()
 	if (d->group_level_ == 0) {
 		// create a new group
 		++d->group_id_;
-		LYXERR(Debug::UNDO, "+++++++Creating new group " << d->group_id_);
+		LYXERR(Debug::UNDO, "+++++++ Creating new group " << d->group_id_
+		       << " for buffer " << &d->buffer_);
 	}
 	++d->group_level_;
 }
@@ -586,7 +587,8 @@ void Undo::endUndoGroup()
 	if (d->group_level_ == 0) {
 		// real end of the group
 		d->group_cur_before_ = CursorData();
-		LYXERR(Debug::UNDO, "-------End of group " << d->group_id_);
+		LYXERR(Debug::UNDO, "------- End of group " << d->group_id_
+		       << " of buffer " << &d->buffer_);
 	}
 }
 
diff --git a/src/frontends/qt4/GuiApplication.cpp b/src/frontends/qt4/GuiApplication.cpp
index 1e847464d8..97a60e9b44 100644
--- a/src/frontends/qt4/GuiApplication.cpp
+++ b/src/frontends/qt4/GuiApplication.cpp
@@ -1407,7 +1407,7 @@ DispatchResult const & GuiApplication::dispatch(FuncRequest const & cmd)
 	updateCurrentView(cmd, dr);
 
 	// the buffer may have been closed by one action
-	if (theBufferList().isLoaded(buffer))
+	if (theBufferList().isLoaded(buffer) || theBufferList().isInternal(buffer))
 		buffer->undo().endUndoGroup();
 
 	d->dispatch_result_ = dr;
@@ -1883,7 +1883,7 @@ void GuiApplication::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 			dispatch(func);
 		}
 		// the buffer may have been closed by one action
-		if (theBufferList().isLoaded(buffer))
+		if (theBufferList().isLoaded(buffer) || theBufferList().isInternal(buffer))
 			buffer->undo().endUndoGroup();
 		break;
 	}