It looks like this code is clipped from the WbWindowsHTMLHelpAccessor class>>#helpFor:helpFile:topic:title:command: method -- is that right?
I think the code should be something between what is there now and what you suggest:
self htmlHelpPlatformFunction
callWith: shellWindowHandle "window handle that the help will be associated with"
with: helpFilePath asPSZ "your .CHM file name"
with: helpContextCommand
with: aTopicId asInteger "the map id from the help file"
Using asPSZ is slightly more efficient than using nullTerminated since it will not make a copy of the string if it is already null terminated.
There is no need to null terminate aTopicId (and, in fact, it won't work since aTopicId can be nil).
What do you think?
John