v2gitk: Show patch for initial commit

> Make gitk show the patch for the initial commit by default.
> Override with log.showroot.
> 
> Signed-off-by: Marcus Karlsson<mk@acc.umu.se>
> ---
>   gitk-git/gitk |   13 +++++++++++--
>   1 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/gitk-git/gitk b/gitk-git/gitk
> index 4cde0c4..40ea73f 100755
> --- a/gitk-git/gitk
> +++ b/gitk-git/gitk
> @@ -7402,7 +7402,7 @@ proc addtocflist {ids} {
>   }
> 
>   proc diffcmd {ids flags} {
> -    global nullid nullid2
> +    global log_showroot nullid nullid2
> 
>       set i [lsearch -exact $ids $nullid]
>       set j [lsearch -exact $ids $nullid2]
> @@ -7436,7 +7436,11 @@ proc diffcmd {ids flags} {
>   	    lappend cmd HEAD
>   	}
>       } else {
> -	set cmd [concat | git diff-tree -r $flags $ids]
> +	set cmd [concat | git diff-tree -r]
> +	if {$log_showroot eq true} {
> +	    set cmd [concat $cmd --root]
> +	}
> +	set cmd [concat $cmd $flags $ids]
>       }
>       return $cmd
>   }
> @@ -11403,6 +11407,11 @@ catch {
>       }
>   }
> 
> +set log_showroot true
> +catch {
> +    set log_showroot [exec git config --get log.showroot]
> +}
> +
>   if {[tk windowingsystem] eq "aqua"} {
>       set mainfont {{Lucida Grande} 9}
>       set textfont {Monaco 9}

> [cc: Paul Mackerras]
> 
> Hi,
> I think that the historical explanation that Junio gave could
> be used as a basis for a commit message:
> 
>   In early days, all projects managed by git (except for git itself) had the
>   product of a fairly mature development history in their first commit, and
>   it was deemed unnecessary clutter to show additions of these thousands of
>   paths as a patch.
> 
>   "git log" learned to show the patch for the initial commit without requiring
>   --root command line option at 0f03ca9 (config option log.showroot to show
>   the diff of root commits, 2006-11-23).
> 
>   Teach gitk to respect log.showroot.

> Also the gitk should be mentioned in the man-page for git-config log.showroot.
> The current description of this option seems suboptimal because it explains
> how it used to be, which is not really relevant:
>   log.showroot
>     If true, the initial commit will be shown as a big creation event. This is
>     equivalent to a diff against an empty tree. Tools like git-log(1) or git-
>     whatchanged(1), which normally hide the root commit will now show it. True by
>     default.
> This could be changed to:
>     If true (the default), the root commit will be shown as a big creation
>     event --- a diff against an empty tree. This diff can be very large for
>     a project which was imported into git after some development history.
>     If log.showroot is false tools like git-log(1), git-whatchanged(1), or
>     gitk(1) will not display the added files.

>> Also the gitk should be mentioned in the man-page for git-config log.showroot.
>> The current description of this option seems suboptimal because it explains
>> how it used to be, which is not really relevant:
>>   log.showroot
>>     If true, the initial commit will be shown as a big creation event. This is
>>     equivalent to a diff against an empty tree. Tools like git-log(1) or git-
>>     whatchanged(1), which normally hide the root commit will now show it. True by
>>     default.
>> This could be changed to:
>>     If true (the default), the root commit will be shown as a big creation
>>     event --- a diff against an empty tree. This diff can be very large for
>>     a project which was imported into git after some development history.
>>     If log.showroot is false tools like git-log(1), git-whatchanged(1), or
>>     gitk(1) will not display the added files.
>
> I agree, but that feels like something that could be made into a
> separate patch. Or should I include that too?