gitk: have callers of diffcmd supply pipe symbol when necessary

Function 'diffcmd' derives which of git diff-files, git diff-index, or
git diff-tree must be invoked depending on the ids provided. It puts
the pipe symbol as the first element of the returned command list.

Note though that of the four callers only two use the command with
Tcl 'open' and need the pipe symbol. The other two callers pass the
command to Tcl 'exec' and must remove the pipe symbol.

Do not include the pipe symbol in the constructed command list, but let
the call sites decide whether to add it or not. Note that Tcl 'open'
inspects only the first character of the command list, which is also
the first character of the first element in the list. For this reason,
it is valid to just tack on the pipe symbol with |$cmd and it is not
necessary to use [concat | $cmd].

Signed-off-by: Johannes Sixt <[email protected]>

Signed-off-by: Taylor Blau <[email protected]>

Author: j6t

gitk

@@ -7892,15 +7892,15 @@ proc diffcmd {ids flags} {
     if {$i >= 0} {
         if {[llength $ids] > 1 && $j < 0} {
             # comparing working directory with some specific revision
-            set cmd [concat | git diff-index $flags]
+            set cmd [concat git diff-index $flags]
             if {$i == 0} {
                 lappend cmd -R [lindex $ids 1]
             } else {
                 lappend cmd [lindex $ids 0]
             }
         } else {
             # comparing working directory with index
-            set cmd [concat | git diff-files $flags]
+            set cmd [concat git diff-files $flags]
             if {$j == 1} {
                 lappend cmd -R
             }
@@ -7909,7 +7909,7 @@ proc diffcmd {ids flags} {
         if {[package vcompare $git_version "1.7.2"] >= 0} {
             set flags "$flags --ignore-submodules=dirty"
         }
-        set cmd [concat | git diff-index --cached $flags]
+        set cmd [concat git diff-index --cached $flags]
         if {[llength $ids] > 1} {
             # comparing index with specific revision
             if {$j == 0} {
@@ -7925,7 +7925,7 @@ proc diffcmd {ids flags} {
         if {$log_showroot} {
             lappend flags --root
         }
-        set cmd [concat | git diff-tree -r $flags $ids]
+        set cmd [concat git diff-tree -r $flags $ids]
     }
     return $cmd
 }
@@ -7937,7 +7937,7 @@ proc gettreediffs {ids} {
     if {$limitdiffs && $vfilelimit($curview) ne {}} {
             set cmd [concat $cmd -- $vfilelimit($curview)]
     }
-    if {[catch {set gdtf [open $cmd r]}]} return
+    if {[catch {set gdtf [open |$cmd r]}]} return
 
     set treepending $ids
     set treediff {}
@@ -8057,7 +8057,7 @@ proc getblobdiffs {ids} {
     if {$limitdiffs && $vfilelimit($curview) ne {}} {
         set cmd [concat $cmd -- $vfilelimit($curview)]
     }
-    if {[catch {set bdf [open $cmd r]} err]} {
+    if {[catch {set bdf [open |$cmd r]} err]} {
         error_popup [mc "Error getting diffs: %s" $err]
         return
     }
@@ -9080,8 +9080,6 @@ proc getpatchid {id} {
 
     if {![info exists patchids($id)]} {
         set cmd [diffcmd [list $id] {-p --root}]
-        # trim off the initial "|"
-        set cmd [lrange $cmd 1 end]
         if {[catch {
             set x [eval exec $cmd | git patch-id]
             set patchids($id) [lindex $x 0]
@@ -9326,8 +9324,6 @@ proc mkpatchgo {} {
     set newid [$patchtop.tosha1 get]
     set fname [$patchtop.fname get]
     set cmd [diffcmd [list $oldid $newid] -p]
-    # trim off the initial "|"
-    set cmd [lrange $cmd 1 end]
     lappend cmd >$fname &
     if {[catch {eval exec $cmd} err]} {
         error_popup "[mc "Error creating patch:"] $err" $patchtop