Regression in the XmlBaseWriter.cs

[marcin-krystianc]

Description

In this optimization change (XmlBaseWriter.cs), there is a mistake which changes the logic in the XmlBaseWriter.cs. Previously, it checked for the existence of - at the end of a text, but now it is checked at the beginning of the text.

Reproduction Steps

Use .NET 7 preview 1 and run this command for any F# project:
dotnet msbuild /t:build /pp /p:TargetFramework=net7.0 MyFsharpProject.fsharp
It fails to write for example this element (which exists there for about 5 years)

Expected behavior

Shouldn't throw an exception

Actual behavior

throws an exception:

System.ArgumentException: An XML comment cannot contain '--', and '-' cannot be the last character.
   at System.Xml.XmlTextWriter.WriteComment(String text)
   at System.Xml.XmlElement.WriteElementTo(XmlWriter writer, XmlElement el)
   at System.Xml.XmlDocument.Save(XmlWriter w)
   at Microsoft.Build.Evaluation.Project.ProjectImpl.SaveLogicalProject(TextWriter writer)
   at Microsoft.Build.CommandLine.MSBuildApp.BuildProject(String projectFile, String[] targets, String toolsVersion, Dictionary`2 globalProperties, Dictionary`2 restoreProperties, ILogger[] loggers, LoggerVerbosity verbosity, DistributedLoggerRecord[] distributedLoggerRecords, Int32 cpuCount, Boolean enableNodeReuse, TextWriter preprocessWriter, TextWriter targetsWriter, Boolean detailedSummary, ISet`1 warningsAsErrors, ISet`1 warningsNotAsErrors, ISet`1 warningsAsMessages, Boolean enableRestore, ProfilerLogger profilerLogger, Boolean enableProfiler, Boolean interactive, Boolean isolateProjects, GraphBuildOptions graphBuildOptions, Boolean lowPriority, String[] inputResultsCaches, String outputResultsCache, String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
Unhandled exception: System.ArgumentException: An XML comment cannot contain '--', and '-' cannot be the last character.
   at System.Xml.XmlTextWriter.WriteComment(String text)
   at System.Xml.XmlElement.WriteElementTo(XmlWriter writer, XmlElement el)
   at System.Xml.XmlDocument.Save(XmlWriter w)
   at Microsoft.Build.Evaluation.Project.ProjectImpl.SaveLogicalProject(TextWriter writer)
   at Microsoft.Build.CommandLine.MSBuildApp.BuildProject(String projectFile, String[] targets, String toolsVersion, Dictionary`2 globalProperties, Dictionary`2 restoreProperties, ILogger[] loggers, LoggerVerbosity verbosity, DistributedLoggerRecord[] distributedLoggerRecords, Int32 cpuCount, Boolean enableNodeReuse, TextWriter preprocessWriter, TextWriter targetsWriter, Boolean detailedSummary, ISet`1 warningsAsErrors, ISet`1 warningsNotAsErrors, ISet`1 warningsAsMessages, Boolean enableRestore, ProfilerLogger profilerLogger, Boolean enableProfiler, Boolean interactive, Boolean isolateProjects, GraphBuildOptions graphBuildOptions, Boolean lowPriority, String[] inputResultsCaches, String outputResultsCache, String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Main(String[] args)
   at Microsoft.DotNet.Cli.Utils.MSBuildForwardingAppWithoutLogging.ExecuteInProc(String[] arguments)

Regression?

yes

Known Workarounds

no

Configuration

No response

Other information

FYI @GrabYourPitchforks

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Issue Details

---

Description

In this optimization change (XmlBaseWriter.cs), there is a mistake which changes the logic in the XmlBaseWriter.cs. Previously, it checked for the existence of - at the end of a text, but now it is checked at the beginning of the text.

Reproduction Steps

Use .NET 7 preview 1 and run this command for any F# project:
dotnet msbuild /t:build /pp /p:TargetFramework=net7.0 MyFsharpProject.fsharp
It fails to write for example this element (which exists there for about 5 years)

Expected behavior

Shouldn't throw an exception

Actual behavior

throws an exception:

System.ArgumentException: An XML comment cannot contain '--', and '-' cannot be the last character.
   at System.Xml.XmlTextWriter.WriteComment(String text)
   at System.Xml.XmlElement.WriteElementTo(XmlWriter writer, XmlElement el)
   at System.Xml.XmlDocument.Save(XmlWriter w)
   at Microsoft.Build.Evaluation.Project.ProjectImpl.SaveLogicalProject(TextWriter writer)
   at Microsoft.Build.CommandLine.MSBuildApp.BuildProject(String projectFile, String[] targets, String toolsVersion, Dictionary`2 globalProperties, Dictionary`2 restoreProperties, ILogger[] loggers, LoggerVerbosity verbosity, DistributedLoggerRecord[] distributedLoggerRecords, Int32 cpuCount, Boolean enableNodeReuse, TextWriter preprocessWriter, TextWriter targetsWriter, Boolean detailedSummary, ISet`1 warningsAsErrors, ISet`1 warningsNotAsErrors, ISet`1 warningsAsMessages, Boolean enableRestore, ProfilerLogger profilerLogger, Boolean enableProfiler, Boolean interactive, Boolean isolateProjects, GraphBuildOptions graphBuildOptions, Boolean lowPriority, String[] inputResultsCaches, String outputResultsCache, String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
Unhandled exception: System.ArgumentException: An XML comment cannot contain '--', and '-' cannot be the last character.
   at System.Xml.XmlTextWriter.WriteComment(String text)
   at System.Xml.XmlElement.WriteElementTo(XmlWriter writer, XmlElement el)
   at System.Xml.XmlDocument.Save(XmlWriter w)
   at Microsoft.Build.Evaluation.Project.ProjectImpl.SaveLogicalProject(TextWriter writer)
   at Microsoft.Build.CommandLine.MSBuildApp.BuildProject(String projectFile, String[] targets, String toolsVersion, Dictionary`2 globalProperties, Dictionary`2 restoreProperties, ILogger[] loggers, LoggerVerbosity verbosity, DistributedLoggerRecord[] distributedLoggerRecords, Int32 cpuCount, Boolean enableNodeReuse, TextWriter preprocessWriter, TextWriter targetsWriter, Boolean detailedSummary, ISet`1 warningsAsErrors, ISet`1 warningsNotAsErrors, ISet`1 warningsAsMessages, Boolean enableRestore, ProfilerLogger profilerLogger, Boolean enableProfiler, Boolean interactive, Boolean isolateProjects, GraphBuildOptions graphBuildOptions, Boolean lowPriority, String[] inputResultsCaches, String outputResultsCache, String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Execute(String[] commandLine)
   at Microsoft.Build.CommandLine.MSBuildApp.Main(String[] args)
   at Microsoft.DotNet.Cli.Utils.MSBuildForwardingAppWithoutLogging.ExecuteInProc(String[] arguments)

Regression?

yes

Known Workarounds

no

Configuration

No response

Other information

FYI @GrabYourPitchforks

Author:	marcin-krystianc
Assignees:	-
Labels:	area-System.Xml
Milestone:	-

[krwq]

cc: @GrabYourPitchforks

[GrabYourPitchforks]

Thanks for the report! I'll send a PR fixing this (and adding regression tests) within a few hours.

[GrabYourPitchforks]

Double-checked the original PR to look for additional errors. Buggy lines:

• eeeeb7a#diff-623f899046e92b4f3466d81f642abd32a22cec9ba0fe81917b4121a6066ccc68R445 (was already fixed by DCS alignment to 4.8 with schema support #71752)
• eeeeb7a#diff-5a4227ea7ed09c1330ccd8c1706b184096516ec666ec72f1cc98864f1d11a32fR766