Version 1.7+ - System.ExecutionEngineException and System.AccessViolationException about ifiltertextreader

[Happi-cat]

Played a bit with code and my samples and got it working with next change #47
Would be good to review/validate that fix.

Few notes about AcessViolationException I've got in my app:

• I was getting AcccessViolationException from time to time in .net472 app when tried to process batch of files in the same process. And wasn't getting error when tried to process one file per new process.
• Was getting AccessViolation all the time in .net5 app

[JohZant]

Tested it out and so far, so good.

[Sicos1977]

Nice and all credits go to @Happi-cat

[gakera]

We are seeing a System.AccessViolationException in IFilterTextReader Version=1.7.3 after upgrading to .net 5 - but it does not happen on .net 3.1

I haven't stepped into the library code, but we are just calling ReadToEnd and I assume it's similar location:

Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at System.Runtime.InteropServices.Marshal.Release(IntPtr)
   at IFilterTextReader.FilterReader.Read(Char[], Int32, Int32)
   at IFilterTextReader.FilterReader.ReadLine()
   at IFilterTextReader.FilterReader.ReadToEnd()

I will try version 1.6.5 of the library, to see if that fixes this.

Update: after changing version to 1.6.5, I don't get this error anymore.

[Sicos1977]

The only change that could explain the memory acces violation is this one I guess..

                        finally
                        {
                            if (valuePtr != IntPtr.Zero)
                                Marshal.Release(valuePtr);
                        }

Could you try the latest version with this removed and see if that solves it?

[Sicos1977]

Try version 1.7.4 and see if that fixes it. I just try to catch te exception because I have no idea what is going wrong. I do exactly what needed to be done to free the pointers and memory.

[gakera]

I was trying to set up a small test in our regulatory compliance test project, and I have the same problem that is probably what is happening in your new version 1.7.4: AccessViolationExceptions can't be caught and handled in the try / catch blocks. They are always thrown as unhandled. So for now, the only workaround for me is to use a version which doesn't throw this exception, and we were used to using 1.6.4 so I'll continue using that.

[Sicos1977]

Ok learned something new here. Well if you have a document that can reprodure the error it would be helpfull.

[gakera]

Attached is just newly created .doc file, which fails when I try ReadToEnd().

Sicos1977.zip

Relevant failing code:

var fromPath = @"C:\Sicos1977.doc";
var reader = new FilterReader(fromPath, ".doc");
var txt = reader.ReadToEnd();

tested on 1.7.4 and AccessViolationException is thrown.

[Sicos1977]

Whatever I try I just can't reproduce the error, it just works fine on my system.

[gakera]

Visual Studio 2019 on Windows 10 here, not sure if that would make a difference? This also is running in a .net 5 project
<TargetFramework>net5.0</TargetFramework>

[Sicos1977]

I tested it on Windows 10 and on Windows 2012 R2 server and on both system everything works fine.

[JohZant]

Well, if @gakera is having success on .net 3.1, I am hoping that my issue may possibly be something that I am doing wrong. So, at the risk of outing myself as an idiot, I have added a console app to a fork located here.

Change the DirectoryPath at the start of the main method to where ever your documents are located and it will try and read them all. I only put the Sicos1977.doc file from #46 (comment) in my folder and I get the following error:

Fatal error. Internal CLR error. (0x80131506)
   at System.Runtime.InteropServices.Marshal.Release(IntPtr)
   at IFilterTextReader.FilterReader.Read(Char[], Int32, Int32)
   at IFilterTextReader.FilterReader.ReadLine()
   at IFilterTextReader.FilterReader.ReadToEnd()
   at ConsoleApp1.Program.TryReadFile(System.IO.FileInfo)
   at ConsoleApp1.Program.Main(System.String[])

When debugging, the exception message says Exception of type 'System.ExecutionEngineException' was thrown.

Edit: When I test it on the ConsoleApp1 with .Net 5.0, I am getting the AccessViolationException error.

[gakera]

I modified @JohZant's console app to reflect my use, and I have the same results.
https://github.com/gakera/IFilterTextReader

.net3.1 throws ExecutionEngineException, .net 5 throws AccessViolationException.

[RockNHawk]

Attached is just newly created .doc file, which fails when I try ReadToEnd().

Sicos1977.zip

Relevant failing code:

var fromPath = @"C:\Sicos1977.doc";
var reader = new FilterReader(fromPath, ".doc");
var txt = reader.ReadToEnd();

tested on 1.7.4 and AccessViolationException is thrown.

I have same results. I retargeting the IFilterTextViewer.csproj to net5.0-windows , read some file get the same result.

But this file Sicos1977.doc works well.

IFilterTextViewer.csproj for net5.0-windows :

<?xml version="1.0" encoding="utf-8"?>
<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
  <PropertyGroup>
	<OutputType>WinExe</OutputType>
	<TargetFramework>net5.0-windows</TargetFramework>
	<UseWindowsForms>true</UseWindowsForms>
	<EnableDefaultCompileItems>false</EnableDefaultCompileItems>
	<EnableDefaultContentItems>false</EnableDefaultContentItems>
	<EnableDefaultEmbeddedResourceItems>false</EnableDefaultEmbeddedResourceItems>
	<GenerateAssemblyInfo>false</GenerateAssemblyInfo>
	<GenerateResourceUsePreserializedResources>true</GenerateResourceUsePreserializedResources>
  </PropertyGroup>
  
<PropertyGroup>
	<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
	<Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
	<ProjectGuid>{7E0C9F1B-0E41-4653-BE50-187566FB82EC}</ProjectGuid>
	<OutputType>WinExe</OutputType>
	<AppDesignerFolder>Properties</AppDesignerFolder>
	<RootNamespace>IFilterTextViewer</RootNamespace>
	<AssemblyName>IFilterTextViewer</AssemblyName>
	<TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
	<FileAlignment>512</FileAlignment>
	<TargetFrameworkProfile />
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
	<PlatformTarget>AnyCPU</PlatformTarget>
	<DebugSymbols>true</DebugSymbols>
	<DebugType>full</DebugType>
	<Optimize>false</Optimize>
	<OutputPath>bin\Debug\</OutputPath>
	<DefineConstants>DEBUG;TRACE</DefineConstants>
	<ErrorReport>prompt</ErrorReport>
	<WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
	<PlatformTarget>AnyCPU</PlatformTarget>
	<DebugType>pdbonly</DebugType>
	<Optimize>true</Optimize>
	<OutputPath>bin\Release\</OutputPath>
	<DefineConstants>TRACE</DefineConstants>
	<ErrorReport>prompt</ErrorReport>
	<WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
	<DebugSymbols>true</DebugSymbols>
	<OutputPath>bin\x86\Debug\</OutputPath>
	<DefineConstants>DEBUG;TRACE</DefineConstants>
	<DebugType>full</DebugType>
	<PlatformTarget>x86</PlatformTarget>
	<ErrorReport>prompt</ErrorReport>
	<CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
	<OutputPath>bin\x86\Release\</OutputPath>
	<DefineConstants>TRACE</DefineConstants>
	<Optimize>true</Optimize>
	<DebugType>pdbonly</DebugType>
	<PlatformTarget>x86</PlatformTarget>
	<ErrorReport>prompt</ErrorReport>
	<CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
  </PropertyGroup>
  <PropertyGroup>
	<ApplicationIcon>filter.ico</ApplicationIcon>
  </PropertyGroup>
<!--  <ItemGroup>-->
<!--    <Reference Include="Microsoft.Win32.Registry, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">-->
<!--      <HintPath>..\packages\Microsoft.Win32.Registry.5.0.0\lib\net461\Microsoft.Win32.Registry.dll</HintPath>-->
<!--    </Reference>-->
<!--    <Reference Include="System" />-->
<!--    <Reference Include="System.Data">-->
<!--      <HintPath>C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.8\System.Data.dll</HintPath>-->
<!--    </Reference>-->
<!--    <Reference Include="System.Drawing" />-->
<!--    <Reference Include="System.Security.AccessControl, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">-->
<!--      <HintPath>..\packages\System.Security.AccessControl.5.0.0\lib\net461\System.Security.AccessControl.dll</HintPath>-->
<!--    </Reference>-->
<!--    <Reference Include="System.Security.Principal.Windows, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">-->
<!--      <HintPath>..\packages\System.Security.Principal.Windows.5.0.0\lib\net461\System.Security.Principal.Windows.dll</HintPath>-->
<!--    </Reference>-->
<!--    <Reference Include="System.Windows.Forms" />-->
<!--  </ItemGroup>-->
  <ItemGroup>
	<Compile Include="Reader.cs" />
	<Compile Include="MainForm.cs">
	  <SubType>Form</SubType>
	</Compile>
	<Compile Include="MainForm.Designer.cs">
	  <DependentUpon>MainForm.cs</DependentUpon>
	</Compile>
	<Compile Include="Program.cs" />
	<Compile Include="Properties\AssemblyInfo.cs" />
	<EmbeddedResource Include="MainForm.resx">
	  <DependentUpon>MainForm.cs</DependentUpon>
	</EmbeddedResource>
	<EmbeddedResource Include="Properties\Resources.resx">
	  <Generator>ResXFileCodeGenerator</Generator>
	  <LastGenOutput>Resources.Designer.cs</LastGenOutput>
	  <SubType>Designer</SubType>
	</EmbeddedResource>
	<Compile Include="Properties\Resources.Designer.cs">
	  <AutoGen>True</AutoGen>
	  <DependentUpon>Resources.resx</DependentUpon>
	  <DesignTime>True</DesignTime>
	</Compile>
	<None Include="app.config" />
	<None Include="packages.config" />
	<None Include="Properties\Settings.settings">
	  <Generator>SettingsSingleFileGenerator</Generator>
	  <LastGenOutput>Settings.Designer.cs</LastGenOutput>
	</None>
	<Compile Include="Properties\Settings.Designer.cs">
	  <AutoGen>True</AutoGen>
	  <DependentUpon>Settings.settings</DependentUpon>
	  <DesignTimeSharedInput>True</DesignTimeSharedInput>
	</Compile>
  </ItemGroup>
  <ItemGroup>
	<ProjectReference Include="..\IFilterTextReader\IFilterTextReader.csproj">
	  <Project>{86693e2d-c3cb-4e16-9684-94445934a9d3}</Project>
	  <Name>IFilterTextReader</Name>
	</ProjectReference>
  </ItemGroup>
  <ItemGroup>
	<Content Include="filter.ico" />
  </ItemGroup>
  <ItemGroup>
	<PackageReference Include="Microsoft.Win32.Registry" Version="6.0.0-preview.1.21102.12" />
	<PackageReference Include="System.Resources.Extensions" Version="6.0.0-preview.1.21102.12" />
	<PackageReference Include="System.Security.AccessControl" Version="6.0.0-preview.1.21102.12" />
	<PackageReference Include="System.Security.Principal.Windows" Version="6.0.0-preview.1.21102.12" />
  </ItemGroup>
</Project>

[Sicos1977]

I just uploaded a new package to nuget