Summary

When a property is obtained through InstallScript with MSIGetProperty, it contains additional buffer space on the end.

Symptoms

When a property is obtained within InstallScript, the property will contain additional buffer space at its end. Normally, this buffer space can be disregarded as the property itself is null terminated. In some cases, such as attempting to pass the property though VBScript's RegExp object, this buffer space will interfere.

Resolution

It is considered a best practice to immediately remove the buffer after the property has been retrieved but before it is actually used. This can be done as in the following example:

// retrieve the property
Resize(svUserEmail, nvSize); // or Maybe Resize(svUserEmail, StrLength(svUserEmail)); 
?// use the property

As the comment above suggests, rather than supply the static size of the property it is possible to dynamically trim the buffer by passing the size in as the length of the actual property. As StrLength does not consider the buffer, the size passed in will be correct.