[Tcl-bugs] [ tcl-Bugs-3570244 ] "cd .." behaves wrong if last element in pwd is a symlink

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Bugs item #3570244, was opened at 2012-09-20 14:26
Message generated for change (Comment added) made by wastl-nagel
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Category: 37. File System
Group: obsolete: 8.5.11
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Sebastian Nagel (wastl-nagel)
Assigned to: Don Porter (dgp)
Summary: "cd .." behaves wrong if last element in pwd is a symlink

Initial Comment:
If the last element of a the current path (pwd) is a symbolic link with a trailing slash the command
  cd ..
does not change into the parent directory but stays in the current directory.

In addition, when the link target is a relative path containing ".." or "." the pwd after "cd .." may require normalization.

Related / possible duplicate of "cd .. from link in Windows confuses Tcl - ID: 3183016"


bash> pwd
/tmp/test
bash> mkdir /tmp/dir
bash> ln -sf /tmp/dir link_abs
bash> tclsh
% cd link_abs
% pwd
/tmp/test/link_abs
% cd ..
% pwd  ;# ok we are in /tmp (/tmp/test would be also plausible)
/tmp
% exit

bash> ln -sf /tmp/dir/ link_abs_trailing_slash
bash> tclsh
% cd link_abs_trailing_slash
% pwd
/tmp/test/link_abs_trailing_slash
% cd ..  ;# should cd to /tmp (or /tmp/test)
% pwd    ;# surprise: we stay in same effective directory
/tmp/dir
% exit

bash> ln -sf /tmp/dir link_rel
bash> tclsh
% cd link_rel
% pwd
/tmp/test/link_rel
% cd ..
% pwd    ;# ok, but should be normalized
/tmp/test/..
% file normalize [pwd] 
/tmp
% exit

bash> ln -sf ../dir/ link_rel_trailing_slash
bash> tclsh
% cd link_rel_trailing_slash
% pwd
/tmp/test/link_rel_trailing_slash
% cd ..
% pwd    ;# surprise
/tmp/dir
% exit

bash> ln -sf ./link_abs link2link
bash> tclsh
% cd link2link
% pwd
/tmp/test/link2link
% cd ..  ;# now we are in /tmp/test (also ok)
% pwd    ;# but should be normalized
/tmp/test/.
% file normalize [pwd] 
/tmp

% puts "$::tcl_patchLevel, $::tcl_platform(os) $::tcl_platform(osVersion)"
8.5.11, Linux 3.2.0-30-generic
% exit


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>Comment By: Sebastian Nagel (wastl-nagel)
Date: 2012-09-21 04:56

Message:
Both 8.5.12 and 8.6b3 are affected as well

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Comment By: Donal K. Fellows (dkf)
Date: 2012-09-21 00:50

Message:
Whatever is going on, it's a feature of the file system engine and not the
[cd] command itself.

I suspect that it depends on what normalization does, and I know that Don
Porter has been doing work in that area relatively recently. Is it possible
to retest with 8.5.12 or 8.6b3?

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