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Re: enlarge MAXSYMLINKS



Again about symbolic links, here is some new inputs:


1) MAXSYMLINKS is no longer used in modern Cygwin's;
   indeed, cygwin-1.5.25-15 uses MAX_LINK_DEPTH and
   cygwin-1.7.0-42 uses SYMLOOP_MAX; both are set to 10
   (in ./winsup/cygwin/path.h for 1.5 and in
   ./winsup/cygwin/include/limits.h for 1.7)

2) whether the filesystem is NTFS or not makes no difference;
   whether the symlinks are created using winsymlinks or nowinsymlinks
   makes no difference

3) the only clean way to make cygwin1.dll accept a chain of 32 symlinks
   (instead of 10) is through recompilation

4) for those interested in not-so-clean items, the following may also work
- for 1.5.25-15 (this one i have tested)
- cd /usr/bin
- cat cygwin1.dll | perl -pi -e 's|\203\275\224\371\377\377\012| \203\275\224\371\377\377\040|' > cygwin1.dll.new
- check that cksum before is 3685478250
- check that cksum after is 3302069714
- set the appropriate permissions/owners/groups etc. on cygwin1.dll.new
- from outside Cygwin (eg. from Windows):
- rename cygwin1.dll into cygwin1.dll.old
- rename cygwin1.dll.new into cygwin1.dll
- for 1.7.0-42 (this one i have not tested, please report if fails)
- same as before, with the -e expression replaced by
-e 's|\203\275\344\355\377\377\013| \203\275\344\355\377\377\041|'
- how you can find these strings yourself:
1) either
- objdump -d cygwin1.dll
- look for path_conv::check(...)
- search into those 1000 lines, trying to make the names to match
- try
2) or
- recompile with SYMLOOP_MAX set to 10 (result1)
- recompile with SYMLOOP_MAX set to 10 (result2)
- recompile with SYMLOOP_MAX set to 32 (result3)
- compare result1 and result2 to discover the impact of current
time in the result
- compare result1 and result3 and eliminate the impact of
current time
- (make sure that compilation options are the same as originally)


5) i would also make the following suggestions:

   1) to enhance cygcheck to report whether a given symlink is
      implemented as a Windows'shortcut or as an adhoc Cygwin symlink
      (although this can be seen easily from outside Windows)

2) to use "#define SYMLOOP_MAX 32" in future Cygwin-1.7


Hope this helps,


Denis Excoffier.


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