From ea8574bc1a13d1f9b83472ea66a953d7ef8a0cda Mon Sep 17 00:00:00 2001
From: Ansgar Becker <ansgarbecker@users.noreply.github.com>
Date: Sun, 4 Apr 2010 23:30:37 +0000
Subject: [PATCH] Fix some AVs around ListTables by reintroducing recently
 deleted connection event OnDBObjectsCleared. Required in cases where cache is
 cleared or refreshed (!) elsewhere and ListTables get repainted later.

---
 source/main.pas             | 13 +++++++++-
 source/mysql_connection.pas | 50 ++++++++++++++++++++-----------------
 2 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/source/main.pas b/source/main.pas
index 8f0697cb..7982a512 100644
--- a/source/main.pas
+++ b/source/main.pas
@@ -802,6 +802,7 @@ type
     procedure SaveQueryMemo(Tab: TQueryTab; Filename: String; OnlySelection: Boolean);
     procedure UpdateFilterPanel(Sender: TObject);
     procedure DatabaseChanged(Database: String);
+    procedure DBObjectsCleared(Database: String);
     function GetBlobContent(Results: TMySQLQuery; Column: Integer): String;
     procedure DoSearchReplace;
     procedure UpdateLineCharPanel;
@@ -2413,6 +2414,7 @@ begin
   ConnectionAttempt := TMySQLConnection.Create(Self);
   ConnectionAttempt.OnLog := LogSQL;
   ConnectionAttempt.OnDatabaseChanged := DatabaseChanged;
+  ConnectionAttempt.OnDBObjectsCleared := DBObjectsCleared;
   ConnectionAttempt.ObjectNamesInSelectedDB := SynSQLSyn1.TableNames;
   ConnectionAttempt.Parameters := Params;
   try
@@ -5079,6 +5081,8 @@ var
 begin
   // Find currently selected database node in database tree,
   // or the parent if a table is currently selected.
+  if csDestroying in ComponentState then
+    Exit;
   s := DBtree.FocusedNode;
   if not Assigned(s) then Result := ''
   else case DBtree.GetNodeLevel(s) of
@@ -6575,6 +6579,13 @@ begin
 end;
 
 
+procedure TMainForm.DBObjectsCleared(Database: String);
+begin
+  if (Database='') or (ActiveDatabase=Database) then
+    InvalidateVT(ListTables, VTREE_NOTLOADED, False);
+end;
+
+
 procedure TMainForm.DBtreeDblClick(Sender: TObject);
 var
   Node: PVirtualNode;
@@ -6621,7 +6632,7 @@ begin
 
   // ReInit tree population
   if DoResetTableCache then begin
-    Connection.ClearDbObjects;
+    Connection.ClearAllDbObjects;
     FreeAndNil(AllDatabases);
   end;
   DBtree.ResetNode(DBTree.GetFirst);
diff --git a/source/mysql_connection.pas b/source/mysql_connection.pas
index f8c471a7..0a34d4bd 100644
--- a/source/mysql_connection.pas
+++ b/source/mysql_connection.pas
@@ -102,6 +102,7 @@ type
       FLogPrefix: String;
       FOnLog: TMySQLLogEvent;
       FOnDatabaseChanged: TMySQLDatabaseEvent;
+      FOnDBObjectsCleared: TMySQLDatabaseEvent;
       FRowsFound: Int64;
       FRowsAffected: Int64;
       FServerVersionUntouched: String;
@@ -153,7 +154,8 @@ type
       function GetDBObjects(db: String; Refresh: Boolean=False): TDBObjectList;
       function GetDBSize(db: String): Int64;
       function DbObjectsCached(db: String): Boolean;
-      procedure ClearDbObjects(db: String='');
+      procedure ClearDbObjects(db: String);
+      procedure ClearAllDbObjects;
       property Parameters: TConnectionParameters read FParameters write FParameters;
       property ThreadId: Cardinal read GetThreadId;
       property ConnectionUptime: Integer read GetConnectionUptime;
@@ -183,6 +185,7 @@ type
       // Events
       property OnLog: TMySQLLogEvent read FOnLog write FOnLog;
       property OnDatabaseChanged: TMySQLDatabaseEvent read FOnDatabaseChanged write FOnDatabaseChanged;
+      property OnDBObjectsCleared: TMySQLDatabaseEvent read FOnDBObjectsCleared write FOnDBObjectsCleared;
   end;
 
 
@@ -268,6 +271,7 @@ begin
   FLastQueryNetworkDuration := 0;
   FLogPrefix := '';
   FIsUnicode := False;
+  FDBObjectLists := TStringList.Create;
   FDBSizes := TStringList.Create;
 end;
 
@@ -967,40 +971,42 @@ begin
   FreeAndNil(FCharsetTable);
   FreeAndNil(FTableEngines);
   FreeAndNil(FInformationSchemaObjects);
-  ClearDbObjects;
+  ClearAllDbObjects;
   FTableEngineDefault := '';
 end;
 
 
-procedure TMySQLConnection.ClearDbObjects(db: String='');
+procedure TMySQLConnection.ClearDbObjects(db: String);
 var
   i, idx: Integer;
 begin
-  // Free all cached database object lists, or, if db is passed, only that one
-  if not Assigned(FDBObjectLists) then
+  // Free cached database object list
+  i := FDBObjectLists.IndexOf(db);
+  if i = -1 then
     Exit;
-  if db <> '' then begin
-    i := FDBObjectLists.IndexOf(db);
-    if i = -1 then
-      Exit;
-    TDBObjectList(FDBObjectLists.Objects[i]).Free;
-    FDBObjectLists.Delete(i);
-    idx := FDBSizes.IndexOfName(db);
-    if idx > -1 then
-      FDBSizes.Delete(idx);
-  end else begin
-    for i:=0 to FDBObjectLists.Count-1 do
-      TDBObjectList(FDBObjectLists.Objects[i]).Free;
-    FreeAndNil(FDBObjectLists);
-    FDBSizes.Clear;
-  end;
+  TDBObjectList(FDBObjectLists.Objects[i]).Free;
+  FDBObjectLists.Delete(i);
+  idx := FDBSizes.IndexOfName(db);
+  if idx > -1 then
+    FDBSizes.Delete(idx);
+  if Assigned(FOnDBObjectsCleared) then
+    FOnDBObjectsCleared(db);
+end;
+
+
+procedure TMySQLConnection.ClearAllDbObjects;
+var
+  i: Integer;
+begin
+  for i:=FDBObjectLists.Count-1 downto 0 do
+    ClearDbObjects(FDBObjectLists[i]);
 end;
 
 
 function TMySQLConnection.DbObjectsCached(db: String): Boolean;
 begin
   // Check if a table list is stored in cache
-  Result := Assigned(FDBObjectLists) and (FDBObjectLists.IndexOf(db) > -1);
+  Result := FDBObjectLists.IndexOf(db) > -1;
 end;
 
 
@@ -1210,8 +1216,6 @@ begin
     Result.Sort;
 
     // Add list of objects in this database to cached list of all databases
-    if not Assigned(FDBObjectLists) then
-      FDBObjectLists := TStringList.Create;
     FDBObjectLists.AddObject(db, Result);
 
     FDBSizes.Values[db] := IntToStr(DBSize);