Fix WcaErrorMessage `cArgs==-1` case.

- Count args before creating message record.
- Document terminating NULL requirement.
- Add terminating NULL in MessageExit* macros.
- Enhance tests for problems encountered fixing this nightmare.

Fixes https://github.com/wixtoolset/issues/issues/7422.
Fixes https://github.com/wixtoolset/issues/issues/7444.

2 files changed, 3 insertions, 1 deletions

diff --git a/src/test/burn/WixTestTools/MSIExec.cs b/src/test/burn/WixTestTools/MSIExec.cs
index 98f54c56..f8c73afc 100644
--- a/src/test/burn/WixTestTools/MSIExec.cs
+++ b/src/test/burn/WixTestTools/MSIExec.cs
@@ -111,7 +111,7 @@ namespace WixTestTools
             this.ForceRestart = false;
             this.PromptRestart = false;
             this.LogFile = String.Empty;
-            this.LoggingOptions = MSIExecLoggingOptions.VOICEWARMUP;
+            this.LoggingOptions = MSIExecLoggingOptions.Log_All_Information | MSIExecLoggingOptions.Verbose_Output | MSIExecLoggingOptions.Extra_Debugging_Information; // `/l*vx`
             this.OtherArguments = String.Empty;
         }
 
diff --git a/src/test/msi/TestData/UtilExtensionUserTests/ProductNonVitalUserGroup/NonVitalUserGroup.wxs b/src/test/msi/TestData/UtilExtensionUserTests/ProductNonVitalUserGroup/NonVitalUserGroup.wxs
index 461648ee..7ab4bbe1 100644
--- a/src/test/msi/TestData/UtilExtensionUserTests/ProductNonVitalUserGroup/NonVitalUserGroup.wxs
+++ b/src/test/msi/TestData/UtilExtensionUserTests/ProductNonVitalUserGroup/NonVitalUserGroup.wxs
@@ -10,12 +10,14 @@
 
     <Fragment>
         <util:Group Id="ShouldNotExist" Name="Should Not Exist" />
+        <util:Group Id="AlsoShouldNotExist" Name="Also Should Not Exist" />
 
         <Component Id="Component1" Guid="00030829-0000-0000-C000-000000000046" Directory="INSTALLFOLDER">
             <File Source="$(sys.SOURCEFILEPATH)" KeyPath="yes" />
 
             <util:User Id="CurrentUser" Name="[LogonUser]" Domain="[%USERDOMAIN]" RemoveOnUninstall="no" Vital="no">
                 <util:GroupRef Id="ShouldNotExist" />
+                <util:GroupRef Id="AlsoShouldNotExist" />
             </util:User>
         </Component>
     </Fragment>