We encountered a doubly freed "C" pointer after calling sqlite3_exec in my custom version of the Microsoft.Data.Sqlite C# method SqliteCommand::ExecuteAnReader which does not call the parent C# class method DbCommand::ExecuteReader which does not use a C# NativeMethod. The C# NativeMethod class has a method for handling garbage collection which I bypasses by calling public virtual void SqliteCommand::ExecuteAnReader(). After using sqlite3_exec to insert 935 rows into the Sqlite3 Vendors table, we got the following error message: *** Error in `/opt/monodevelop/bin/mono': free(): invalid pointer: 0x0000000007b2e018 *** Stacktrace:
at <unknown> <0xffffffff> at (wrapper managed-to-native) object.__icall_wrapper_mono_marshal_free (intptr) <IL 0x0000d, 0xffffffff> at (wrapper managed-to-native) Microsoft.Data.Sqlite.SqliteCommand.sqlite3_exec (Microsoft.Data.Sqlite.Interop.Sqlite3Handle,string,Microsoft.Data.Sqlite.SqliteCommand/FooCallbackType,intptr,string&) <IL 0x0007e, 0xffffffff> at Microsoft.Data.Sqlite.SqliteCommand.ExecuteAnReader () <IL 0x00020, 0x00063> at XMLConverter.Program.InsertTable (string,string,int) <IL 0x00060, 0x0013b> at XMLConverter.Program.Main (string[]) <IL 0x001f2, 0x0062f> at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x00050, 0xffffffff> How might we workaround this problem in C# or alternatively should we investigate the C language function how to add additional C language code around sqlite3_exec()? Any help is greatlly appreciated.
