WinAPI GetFullPathName_() question

[jassing]

When I run this code, it fails if I assign the result to a variable. Any idea why?

Code: Select all

Macro test() ; just to ensure I use the exact same call
  GetFullPathName_( *file, 1000, *full, #NUL )
EndMacro

*file = @"test.txt"
*full= AllocateMemory(1000)
result=0

; This works:
test() ; test w/o using the result
Debug test() ; show the result.

Debug "Now trying to assign it to a variable"
result = test() ; this fails with either debugger crashing or "overflow of dynamic memory"

[mk-soft]

Code: Select all

;-TOP by mk-soft

Procedure.s GetFullPathName(FileName.s)
  Protected r1.s, len
  len = GetFullPathName_(FileName, 0, 0, #Null )
  If len
    r1 = Space(len)
    len = GetFullPathName_(FileName, len, @r1, #Null )
  EndIf
  ProcedureReturn r1
EndProcedure

file.s = OpenFileRequester("Open", "", "", 0)
SetCurrentDirectory(GetPathPart(file))

file = GetFilePart(file)
Debug "Filename: " + file
fullpath.s = GetFullPathName(file)
Debug "Fullpath: " + fullpath

[Axolotl]

Hi, I run your code with a small addition on Win11 and PB 6.04LTS(x86) and PB 6.10 LTS (x64) without any errors.

Code: Select all

Debug "Now trying to assign it to a variable"
result = test() ; this fails with either debugger crashing or "overflow of dynamic memory"
Debug "DEBUG: " + PeekS(*full, result) ; my addition 

Just out of curiosity, why not

Code: Select all

Macro IMHO_Better(FileName) 
  GetCurrentDirectory() + FileName 
EndMacro 

Anyway, the solution by mk-soft is TOP

[jassing]

thanks mk-soft.

Just out of curiosity, why not

Code: Select all

Macro IMHO_Better(FileName) 
  GetCurrentDirectory() + FileName 
EndMacro 

What if the file is elsewhere in the path?

[Axolotl]

....
What if the file is elsewhere in the path?

Well, I only read the article on MSDN (...learn.microsoft....) about the function and I came to the conclusion that it always works with the current directory.
Here's a small collection (pasted from MSDN):

GetFullPathName merges the name of the current drive and directory with a specified file name to determine the full path and file name of a specified file.
....
This function does not verify that the resulting path and file name are valid, or that they see an existing file on the associated volume.
....
Relative paths passed to the GetFullPathName function are interpreted as relative to the process's current directory.
....
Applications should be aware that consecutive calls to the GetFullPathName function with a relative path may produce different results if the current directory changes between the two calls.