Subject: Re: [PATCH v1 03/11] git-gui: guard set/unset of GIT_DIR and GIT_WORK_TREE

From: Mark Levedahl <[email-masked]>
Date: Sat, 16 May 2026 10:25:26 -0400

On 5/15/26 11:58 AM, Johannes Sixt wrote:
> Am 14.05.26 um 16:33 schrieb Mark Levedahl:
>> git-gui unconditionally exports GIT_DIR and GIT_WORK_TREE to the
>> environment, and furthmore unconditionally unsets these in many places.
>> But, GIT_WORK_TREE should be set only if it is not {} as the empty
>> value, really meaning no work-tree is found, causes git to throw fatal
>> errors (git-gui gets the error from branch --show-current).  Fixing this
>> is required to allow blame and browser to operate from a repository
>> without a worktree.
>>
>> Establish a pair of functions to remove GIT_DIR and GIT_WORK_TREE from
>> the environment, avoiding any error if they do not exist. Also, add a
>> function to export these, but export GIT_WORK_TREE only if not empty.
> Good. But as I said in a parallel thread, I actually concur with your
> assessment in the coverletter of this patch series that GIT_WORK_TREE
> should be not set at all. At least in the modes that require a working tree.
>
>> Signed-off-by: Mark Levedahl <[email-masked]>
>> ---
>>  git-gui.sh | 32 ++++++++++++++++++++++----------
>>  1 file changed, 22 insertions(+), 10 deletions(-)
>>
>> diff --git a/git-gui.sh b/git-gui.sh
>> index a951fcd..387cad6 100755
>> --- a/git-gui.sh
>> +++ b/git-gui.sh
>> @@ -1122,6 +1122,22 @@ unset argv0dir
>>  ##
>>  ## repository setup
>>  
>> +proc set_gitdir_vars {} {
>> +	global _gitdir _gitworktree env
>> +	if {$_gitdir ne {}} {
>> +		set env(GIT_DIR) $_gitdir
>> +	}
>> +	if {$_gitworktree ne {}} {
>> +		set env(GIT_WORK_TREE) $_gitworktree
>> +	}
>> +}
>> +
>> +proc unset_gitdir_vars {} {
>> +	global env
>> +	catch {unset env(GIT_DIR)}
>> +	catch {unset env(GIT_WORK_TREE)}
>> +}
>> +
>>  set picked 0
>>  if {[catch {
>>  		set _gitdir $env(GIT_DIR)
>> @@ -1207,8 +1223,8 @@ if {[lindex $_reponame end] eq {.git}} {
>>  	set _reponame [lindex $_reponame end]
>>  }
>>  
>> -set env(GIT_DIR) $_gitdir
>> -set env(GIT_WORK_TREE) $_gitworktree
>> +# Export the final paths
>> +set_gitdir_vars
>>  
>>  ######################################################################
>>  ##
>> @@ -2050,13 +2066,11 @@ proc do_gitk {revs {is_submodule false}} {
>>  			# TODO we could make life easier (start up faster?) for gitk
>>  			# by setting these to the appropriate values to allow gitk
>>  			# to skip the heuristics to find their proper value
>> -			unset env(GIT_DIR)
>> -			unset env(GIT_WORK_TREE)
>> +			unset_gitdir_vars
>>  		}
>>  		safe_exec_bg [concat $cmd $revs "--" "--"]
>>  
>> -		set env(GIT_DIR) $_gitdir
>> -		set env(GIT_WORK_TREE) $_gitworktree
>> +		set_gitdir_vars
>>  		cd $pwd
>>  
>>  		if {[info exists main_status]} {
>> @@ -2084,16 +2098,14 @@ proc do_git_gui {} {
>>  
>>  		# see note in do_gitk about unsetting these vars when
>>  		# running tools in a submodule
>> -		unset env(GIT_DIR)
>> -		unset env(GIT_WORK_TREE)
>> +		unset_gitdir_vars
>>  
>>  		set pwd [pwd]
>>  		cd $current_diff_path
>>  
>>  		safe_exec_bg [concat $exe gui]
>>  
>> -		set env(GIT_DIR) $_gitdir
>> -		set env(GIT_WORK_TREE) $_gitworktree
>> +		set_gitdir_vars
>>  		cd $pwd
>>  
>>  		set status_operation [$::main_status \
> After these changes, a 'global env' probably becomes stale and could be
> removed.
>
> -- Hannes
>
Will update to only ever set GIT_DIR, will still remove GIT_WORK_TREE on unset.

Mark