From 136faab91fe1f21c7efe2208876330ff2c64db0d Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Wed, 25 Aug 2021 12:13:29 +1000
Subject: [PATCH] Fix system tables disappear from dialog after task runs

---
 .../providers/qgsprovidersublayertask.sip.in             | 2 +-
 src/app/qgsprovidersublayersdialog.cpp                   | 2 +-
 src/core/providers/qgsprovidersublayertask.cpp           | 9 +++++++--
 src/core/providers/qgsprovidersublayertask.h             | 4 +++-
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/python/core/auto_generated/providers/qgsprovidersublayertask.sip.in b/python/core/auto_generated/providers/qgsprovidersublayertask.sip.in
index cfaafb4db6f..79911b096f6 100644
--- a/python/core/auto_generated/providers/qgsprovidersublayertask.sip.in
+++ b/python/core/auto_generated/providers/qgsprovidersublayertask.sip.in
@@ -35,7 +35,7 @@ possible, regardless of how expensive this may be.
 %End
   public:
 
-    QgsProviderSublayerTask( const QString &uri );
+    QgsProviderSublayerTask( const QString &uri, bool includeSystemTables );
 %Docstring
 Constructor for QgsProviderSublayerTask, which retrieves sublayer details for the
 specified ``uri``.
diff --git a/src/app/qgsprovidersublayersdialog.cpp b/src/app/qgsprovidersublayersdialog.cpp
index 8b724a08127..b1b48ff8308 100644
--- a/src/app/qgsprovidersublayersdialog.cpp
+++ b/src/app/qgsprovidersublayersdialog.cpp
@@ -163,7 +163,7 @@ QgsProviderSublayersDialog::QgsProviderSublayersDialog( const QString &uri, cons
   if ( QgsProviderUtils::sublayerDetailsAreIncomplete( initialDetails ) )
   {
     // initial details are incomplete, so fire up a task in the background to fully populate the model...
-    mTask = new QgsProviderSublayerTask( uri );
+    mTask = new QgsProviderSublayerTask( uri, true );
     connect( mTask.data(), &QgsProviderSublayerTask::taskCompleted, this, [ = ]
     {
       QList< QgsProviderSublayerDetails > res = mTask->results();
diff --git a/src/core/providers/qgsprovidersublayertask.cpp b/src/core/providers/qgsprovidersublayertask.cpp
index 12107f7947c..a0e2b4e483a 100644
--- a/src/core/providers/qgsprovidersublayertask.cpp
+++ b/src/core/providers/qgsprovidersublayertask.cpp
@@ -21,9 +21,10 @@
 #include "qgsprovidersublayerdetails.h"
 #include "qgsreadwritelocker.h"
 
-QgsProviderSublayerTask::QgsProviderSublayerTask( const QString &uri )
+QgsProviderSublayerTask::QgsProviderSublayerTask( const QString &uri, bool includeSystemTables )
   : QgsTask( tr( "Retrieving layers" ), QgsTask::CanCancel | QgsTask::CancelWithoutPrompt )
   , mUri( uri )
+  , mIncludeSystemTables( includeSystemTables )
 {
 }
 
@@ -39,7 +40,11 @@ bool QgsProviderSublayerTask::run()
 {
   mFeedback = std::make_unique< QgsFeedback >();
 
-  const QList<QgsProviderSublayerDetails> res = QgsProviderRegistry::instance()->querySublayers( mUri, Qgis::SublayerQueryFlag::ResolveGeometryType | Qgis::SublayerQueryFlag::CountFeatures, mFeedback.get() );
+  Qgis::SublayerQueryFlags flags = Qgis::SublayerQueryFlag::ResolveGeometryType | Qgis::SublayerQueryFlag::CountFeatures;
+  if ( mIncludeSystemTables )
+    flags |= Qgis::SublayerQueryFlag::IncludeSystemTables;
+
+  const QList<QgsProviderSublayerDetails> res = QgsProviderRegistry::instance()->querySublayers( mUri, flags, mFeedback.get() );
 
   const QgsReadWriteLocker locker( mLock, QgsReadWriteLocker::Write );
   mResults = res;
diff --git a/src/core/providers/qgsprovidersublayertask.h b/src/core/providers/qgsprovidersublayertask.h
index 4fa3082eb69..de8169a3316 100644
--- a/src/core/providers/qgsprovidersublayertask.h
+++ b/src/core/providers/qgsprovidersublayertask.h
@@ -53,7 +53,7 @@ class CORE_EXPORT QgsProviderSublayerTask : public QgsTask
      * Constructor for QgsProviderSublayerTask, which retrieves sublayer details for the
      * specified \a uri.
      */
-    QgsProviderSublayerTask( const QString &uri );
+    QgsProviderSublayerTask( const QString &uri, bool includeSystemTables );
 
     ~QgsProviderSublayerTask() override;
 
@@ -72,6 +72,8 @@ class CORE_EXPORT QgsProviderSublayerTask : public QgsTask
 
     QString mUri;
 
+    bool mIncludeSystemTables = false;
+
     std::unique_ptr< QgsFeedback > mFeedback;
 
     QList<QgsProviderSublayerDetails> mResults;