file UCP: Dir entries can disappear during non-atomic traversal

...so allow for that by reporting failure to call
osl::DirectoryItem::getFileStatus from TaskManager::getv, and make
XResultSet_impl::OneMore ignore such lost entries.  While there may be
legitimate cases where getFileStatus in getv would fail (and thus SAL_INFO would
be more appropriate), the broken, non-atomic design means that such failure is
likely unexpected (and worth a SAL_WARN).

Occasionally ran into this when building UBSan builds, which sometimes failed in
one of the extras/Gallery_*.mk like

> ucb/source/ucp/file/filrset.cxx:235:60: runtime error: load of value 96, which is not a valid value for type 'bool'
>     #0 0x7f079bff575e in fileaccess::XResultSet_impl::OneMore() ucb/source/ucp/file/filrset.cxx:234:60
>     #1 0x7f079bff823e in fileaccess::XResultSet_impl::next() ucb/source/ucp/file/filrset.cxx:288:16
>     #2 0x7f0800a109a8 in Gallery::ImplLoadSubDirs(INetURLObject const&, bool&) svx/source/gallery2/gallery1.cxx:291:36
>     #3 0x7f0800a0c88c in Gallery::ImplLoad(rtl::OUString const&) svx/source/gallery2/gallery1.cxx:202:5
>     #4 0x7f0800a0bfa5 in Gallery::Gallery(rtl::OUString const&) svx/source/gallery2/gallery1.cxx:167:5
>     #5 0x522e13 in createGallery(rtl::OUString const&) svx/source/gengal/gengal.cxx:62:16
>     #6 0x52979a in createTheme(rtl::OUString const&, rtl::OUString const&, rtl::OUString const&, std::__debug::vector<INetURLObject, std::allocator<INetURLObject> >&, bool) svx/source/gengal/gengal.cxx:76:16
>     #7 0x52853d in GalApp::Main() svx/source/gengal/gengal.cxx:318:9
>     #8 0x7f080f6f8c36 in ImplSVMain() vcl/source/app/svmain.cxx:191:35
>     #9 0x7f080f706571 in SVMain() vcl/source/app/svmain.cxx:229:16
>     #10 0x56aa0a in sal_main() vcl/source/salmain/salmain.cxx:41:12
>     #11 0x56a99f in main vcl/source/salmain/salmain.cxx:35:1
>     #12 0x7f07fbaf5400 in __libc_start_main /usr/src/debug/glibc-2.24-33-ge9e69e4/csu/../csu/libc-start.c:289
>     #13 0x42e219 in _start (instdir/program/gengal.bin+0x42e219)
>
> SUMMARY: AddressSanitizer: undefined-behavior ucb/source/ucp/file/filrset.cxx:235:60 in
> solenv/gbuild/Gallery.mk:58: recipe for target 'workdir/Gallery/education.done' failed

presumably because some other part of the build changed instdir/share/config/
in parallel.  (And doing

> while (touch instdir/share/config/TEST && rm instdir/share/config/TEST); do :; done

in parallel to 'make extras' indeed causes this issue to occur easily.)

Change-Id: I115ac727f99eed209b223d828c33060b275daaaa

3 files changed, 59 insertions, 44 deletions

diff --git a/ucb/source/ucp/file/filrset.cxx b/ucb/source/ucp/file/filrset.cxx
index 29e1b9124784..4cad6911abe2 100644
--- a/ucb/source/ucp/file/filrset.cxx
+++ b/ucb/source/ucp/file/filrset.cxx
@@ -228,8 +228,14 @@ XResultSet_impl::OneMore()
         }
         else if( err == osl::FileBase::E_None )
         {
-            aRow = m_pMyShell->getv(
-                this, m_sProperty, aDirIte, aUnqPath, IsRegular );
+            if (!m_pMyShell->getv(
+                    this, m_sProperty, aDirIte, aUnqPath, IsRegular, aRow ))
+            {
+                SAL_WARN(
+                    "ucb.ucp.file",
+                    "getting dir item in <" << m_aBaseDirectory << "> failed");
+                continue;
+            }
 
             if( m_nOpenMode == ucb::OpenMode::DOCUMENTS && IsRegular )
             {
diff --git a/ucb/source/ucp/file/filtask.cxx b/ucb/source/ucp/file/filtask.cxx
index fbe93ed955f8..e78bb9ed46eb 100644
--- a/ucb/source/ucp/file/filtask.cxx
+++ b/ucb/source/ucp/file/filtask.cxx
@@ -2528,13 +2528,14 @@ TaskManager::commit( const TaskManager::ContentMap::iterator& it,
 // directoryitem, which is returned by osl::DirectoryItem::getNextItem()
 
 
-uno::Reference< sdbc::XRow > SAL_CALL
+bool SAL_CALL
 TaskManager::getv(
     Notifier* pNotifier,
     const uno::Sequence< beans::Property >& properties,
     osl::DirectoryItem& aDirItem,
     OUString& aUnqPath,
-    bool& aIsRegular )
+    bool& aIsRegular,
+    uno::Reference< sdbc::XRow > & row )
 {
     uno::Sequence< uno::Any > seq( properties.getLength() );
 
@@ -2548,57 +2549,64 @@ TaskManager::getv(
                                  osl_FileStatus_Mask_LinkTargetURL );
 
     osl::FileBase::RC aRes = aDirItem.getFileStatus( aFileStatus );
-    if ( aRes == osl::FileBase::E_None )
+    if ( aRes != osl::FileBase::E_None )
     {
-        aUnqPath = aFileStatus.getFileURL();
+        SAL_WARN(
+            "ucb.ucp.file",
+            "osl::DirectoryItem::getFileStatus failed with " << +aRes);
+        return false;
+    }
+
+    aUnqPath = aFileStatus.getFileURL();
 
-        // If the directory item type is a link retrieve the type of the target
+    // If the directory item type is a link retrieve the type of the target
 
-        if ( aFileStatus.getFileType() == osl::FileStatus::Link )
+    if ( aFileStatus.getFileType() == osl::FileStatus::Link )
+    {
+        // Assume failure
+        aIsRegular = false;
+        osl::FileBase::RC result = osl::FileBase::E_INVAL;
+        osl::DirectoryItem aTargetItem;
+        osl::DirectoryItem::get( aFileStatus.getLinkTargetURL(), aTargetItem );
+        if ( aTargetItem.is() )
         {
-            // Assume failure
-            aIsRegular = false;
-            osl::FileBase::RC result = osl::FileBase::E_INVAL;
-            osl::DirectoryItem aTargetItem;
-            osl::DirectoryItem::get( aFileStatus.getLinkTargetURL(), aTargetItem );
-            if ( aTargetItem.is() )
-            {
-                osl::FileStatus aTargetStatus( osl_FileStatus_Mask_Type );
+            osl::FileStatus aTargetStatus( osl_FileStatus_Mask_Type );
 
-                if ( osl::FileBase::E_None ==
-                     ( result = aTargetItem.getFileStatus( aTargetStatus ) ) )
-                    aIsRegular =
-                        aTargetStatus.getFileType() == osl::FileStatus::Regular;
-            }
+            if ( osl::FileBase::E_None ==
+                 ( result = aTargetItem.getFileStatus( aTargetStatus ) ) )
+                aIsRegular =
+                    aTargetStatus.getFileType() == osl::FileStatus::Regular;
         }
-        else
-            aIsRegular = aFileStatus.getFileType() == osl::FileStatus::Regular;
+    }
+    else
+        aIsRegular = aFileStatus.getFileType() == osl::FileStatus::Regular;
 
-        registerNotifier( aUnqPath,pNotifier );
-        insertDefaultProperties( aUnqPath );
-        {
-            osl::MutexGuard aGuard( m_aMutex );
+    registerNotifier( aUnqPath,pNotifier );
+    insertDefaultProperties( aUnqPath );
+    {
+        osl::MutexGuard aGuard( m_aMutex );
 
-            TaskManager::ContentMap::iterator it = m_aContent.find( aUnqPath );
-            commit( it,aFileStatus );
+        TaskManager::ContentMap::iterator it = m_aContent.find( aUnqPath );
+        commit( it,aFileStatus );
 
-            TaskManager::PropertySet::iterator it1;
-            PropertySet& propset = *(it->second.properties);
+        TaskManager::PropertySet::iterator it1;
+        PropertySet& propset = *(it->second.properties);
 
-            for( sal_Int32 i = 0; i < seq.getLength(); ++i )
-            {
-                MyProperty readProp( properties[i].Name );
-                it1 = propset.find( readProp );
-                if( it1 == propset.end() )
-                    seq[i] = uno::Any();
-                else
-                    seq[i] = it1->getValue();
-            }
+        for( sal_Int32 i = 0; i < seq.getLength(); ++i )
+        {
+            MyProperty readProp( properties[i].Name );
+            it1 = propset.find( readProp );
+            if( it1 == propset.end() )
+                seq[i] = uno::Any();
+            else
+                seq[i] = it1->getValue();
         }
-        deregisterNotifier( aUnqPath,pNotifier );
     }
+    deregisterNotifier( aUnqPath,pNotifier );
+
     XRow_impl* p = new XRow_impl( this,seq );
-    return uno::Reference< sdbc::XRow >( p );
+    row = uno::Reference< sdbc::XRow >( p );
+    return true;
 }
 
 
diff --git a/ucb/source/ucp/file/filtask.hxx b/ucb/source/ucp/file/filtask.hxx
index 2a427c6adaa6..24e719b3ebb8 100644
--- a/ucb/source/ucp/file/filtask.hxx
+++ b/ucb/source/ucp/file/filtask.hxx
@@ -585,12 +585,13 @@ namespace fileaccess
         // Special optimized method for getting the properties of a directoryitem, which
         // is returned by osl::DirectoryItem::getNextItem()
 
-        css::uno::Reference< css::sdbc::XRow > SAL_CALL
+        bool SAL_CALL
         getv( Notifier* pNotifier,
               const css::uno::Sequence< css::beans::Property >& properties,
               osl::DirectoryItem& DirItem,
               OUString& aUnqPath,
-              bool&      bIsRegular );
+              bool&      bIsRegular,
+              css::uno::Reference< css::sdbc::XRow > & row );
 
 
         /**