Hello,
tried to reproduce the issue.
I think the problem is that in de::File::parent the method maybeAs()
is called on a NULL pointer.
With the attached patch the crash does not happen.
Kind regards,
Bernhard
# apt install doomsday doomsday-dbgsym doomsday-common-dbgsym
$ gdb -q --args doomsday
Reading symbols from doomsday...Reading symbols from
/usr/lib/debug/.build-id/41/6978915c5c4686da064c7ff3a539ef4336958c.debug...done.
done.
(gdb) run
Starting program: /usr/games/doomsday
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff476092d in __dynamic_cast () from
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0 0x00007ffff476092d in __dynamic_cast () at
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1 0x00007ffff7574d95 in de::filesys::Node::maybeAs<de::Folder>()
(this=<optimized out>) at include/de/filesys/../filesys/node.h:88
#2 0x00007ffff7574d95 in de::File::parent() const (this=<optimized out>) at
src/filesys/file.cpp:114
#3 0x00007ffff757572b in de::File::description() const
(this=this@entry=0x5555560e5850) at src/filesys/file.cpp:146
#4 0x00007ffff757a40e in de::FileSystem::interpret(de::File*) (this=<optimized
out>, sourceData=sourceData@entry=0x5555560e5850) at
src/filesys/filesystem.cpp:147
#5 0x00007ffff7573415 in de::DirectoryFeed::populateFile(de::Folder&,
de::String const&) (this=this@entry=0x55555605e410, folder=..., entryName=...)
at src/filesys/directoryfeed.cpp:120
#6 0x00007ffff7573849 in de::DirectoryFeed::populate(de::Folder&)
(this=0x55555605e410, folder=...) at src/filesys/directoryfeed.cpp:77
#7 0x00007ffff757f011 in de::Folder::populate(de::Folder::PopulationBehavior)
(this=0x5555560dcc80, behavior=de::Folder::PopulateFullTree) at
src/filesys/folder.cpp:193
#8 0x00007ffff757f069 in de::Folder::populate(de::Folder::PopulationBehavior)
(this=0x555556145070, behavior=behavior@entry=de::Folder::PopulateFullTree) at
src/filesys/folder.cpp:203
#9 0x00007ffff757c24d in de::FileSystem::refresh()
(this=this@entry=0x5555560b2a50) at src/filesys/filesystem.cpp:66
#10 0x00007ffff75e9be9 in de::App::Instance::initFileSystem(bool)
(this=0x5555560b2910, allowPlugins=<optimized out>) at src/core/app.cpp:242
#11 0x00007ffff75e5faa in
de::App::initSubsystems(QFlags<de::App::SubsystemInitFlag>)
(this=this@entry=0x7fffffffdd80, flags=...) at src/core/app.cpp:592
#12 0x00007ffff6a43115 in
de::BaseGuiApp::initSubsystems(QFlags<de::App::SubsystemInitFlag>)
(this=0x7fffffffdd70, flags=...) at src/baseguiapp.cpp:106
#13 0x00005555555e48a5 in ClientApp::initialize() (this=0x7fffffffdd70) at
src/clientapp.cpp:350
#14 0x00005555555c8605 in main(int, char**) (argc=<optimized out>,
argv=<optimized out>) at src/main_client.cpp:75
From 1e5dcb1be8049b9169e53e44b9085f9a2c4707fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bernhard=20=C3=9Cbelacker?= <bernha...@mailbox.org>
Date: Tue, 23 May 2017 12:07:38 +0200
Subject: Avoid crash after parent() returning NULL pointer.
https://bugs.debian.org/847651
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff476092d in __dynamic_cast () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0 0x00007ffff476092d in __dynamic_cast () at /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1 0x00007ffff7574d95 in de::filesys::Node::maybeAs<de::Folder>() (this=<optimized out>) at include/de/filesys/../filesys/node.h:88
#2 0x00007ffff7574d95 in de::File::parent() const (this=<optimized out>) at src/filesys/file.cpp:114
#3 0x00007ffff757572b in de::File::description() const (this=this@entry=0x5555560e5850) at src/filesys/file.cpp:146
#4 0x00007ffff757a40e in de::FileSystem::interpret(de::File*) (this=<optimized out>, sourceData=sourceData@entry=0x5555560e5850) at src/filesys/filesystem.cpp:147
#5 0x00007ffff7573415 in de::DirectoryFeed::populateFile(de::Folder&, de::String const&) (this=this@entry=0x55555605e410, folder=..., entryName=...) at src/filesys/directoryfeed.cpp:120
#6 0x00007ffff7573849 in de::DirectoryFeed::populate(de::Folder&) (this=0x55555605e410, folder=...) at src/filesys/directoryfeed.cpp:77
#7 0x00007ffff757f011 in de::Folder::populate(de::Folder::PopulationBehavior) (this=0x5555560dcc80, behavior=de::Folder::PopulateFullTree) at src/filesys/folder.cpp:193
#8 0x00007ffff757f069 in de::Folder::populate(de::Folder::PopulationBehavior) (this=0x555556145070, behavior=behavior@entry=de::Folder::PopulateFullTree) at src/filesys/folder.cpp:203
#9 0x00007ffff757c24d in de::FileSystem::refresh() (this=this@entry=0x5555560b2a50) at src/filesys/filesystem.cpp:66
#10 0x00007ffff75e9be9 in de::App::Instance::initFileSystem(bool) (this=0x5555560b2910, allowPlugins=<optimized out>) at src/core/app.cpp:242
#11 0x00007ffff75e5faa in de::App::initSubsystems(QFlags<de::App::SubsystemInitFlag>) (this=this@entry=0x7fffffffdd80, flags=...) at src/core/app.cpp:592
#12 0x00007ffff6a43115 in de::BaseGuiApp::initSubsystems(QFlags<de::App::SubsystemInitFlag>) (this=0x7fffffffdd70, flags=...) at src/baseguiapp.cpp:106
#13 0x00005555555e48a5 in ClientApp::initialize() (this=0x7fffffffdd70) at src/clientapp.cpp:350
#14 0x00005555555c8605 in main(int, char**) (argc=<optimized out>, argv=<optimized out>) at src/main_client.cpp:75
---
doomsday/libcore/src/filesys/file.cpp | 3 +++
1 file changed, 3 insertions(+)
diff --git a/doomsday/libcore/src/filesys/file.cpp b/doomsday/libcore/src/filesys/file.cpp
index fd9b8dc..a4a21c5 100644
--- a/doomsday/libcore/src/filesys/file.cpp
+++ b/doomsday/libcore/src/filesys/file.cpp
@@ -111,6 +111,9 @@ FileSystem &File::fileSystem()
Folder *File::parent() const
{
+ if (!Node::parent())
+ return NULL;
+
return Node::parent()->maybeAs<Folder>();
}
--
2.11.0
