git-gui: fix concatenation of ui_ready by adding ";"

From: =?UTF-8?q?Ansgar=20R=C3=B6ber?= <[email protected]>

This fixes https://github.com/git-for-windows/git/issues/2469

---
git-gui: fix concatenation of ui_ready by adding ";"

This fixes https://github.com/git-for-windows/git/issues/2469

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-607%2FIsengart%2Ffix-stage-to-commit-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-607/Isengart/fix-stage-to-commit-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/607

 git-gui.sh        | 4 ++--
 lib/index.tcl     | 4 ++--
 lib/mergetool.tcl | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

index 4610e4ca72a..faaf93b431a 100755
@@ -2600,12 +2600,12 @@ proc toggle_or_diff {mode w args} {
 			update_indexinfo \
 				"Unstaging [short_path $path] from commit" \
 				[list $path] \
-				[concat $after [list ui_ready]]
+				[concat $after {ui_ready;}]
 		} elseif {$w eq $ui_workdir} {
 			update_index \
 				"Adding [short_path $path]" \
 				[list $path] \
-				[concat $after [list ui_ready]]
+				[concat $after {ui_ready;}]
 		}
 	} else {
 		set selected_paths($path) 1

index 1fc5b42300d..59d1f7542a8 100644
@@ -60,7 +60,7 @@ proc rescan_on_error {err {after {}}} {
 
 	$::main_status stop_all
 	unlock_index
-	rescan [concat $after [list ui_ready]] 0
+	rescan [concat $after {ui_ready;}] 0
 }
 
 proc update_indexinfo {msg path_list after} {

@@ -314,7 +314,7 @@ proc unstage_helper {txt paths} {
 		update_indexinfo \
 			$txt \
 			$path_list \
-			[concat $after [list ui_ready]]
+			[concat $after {ui_ready;}]
 	}
 }
 

index 120bc4064b6..e688b016ef6 100644
@@ -59,7 +59,7 @@ proc merge_add_resolution {path} {
 	update_index \
 		[mc "Adding resolution for %s" [short_path $path]] \
 		[list $path] \
-		[concat $after [list ui_ready]]
+		[concat $after {ui_ready;}]
 }
 
 proc merge_force_stage {stage} {

base-commit: a5728022e07c53e5ac91db0960870518e243b7c1

gitgitgadget

Hi Ansgar,

Sorry for the late reply. Thanks for the patch. The code changes all look correct, other than one extra hunk I suggest (see below). The commit subject and message not so much.

We aren't fixing concatenation of "ui_ready". We are fixing a syntax error because we didn't add a statement separator (semicolon), and so if we later append something else, it would be treated as an argument to the ui_ready call by Tcl, causing a syntax error.

Instead of linking to another project's GitHub, describe the problem and its solution in the commit message.

So, based on the suggestions, I propose the following commit message:

Subject: git-gui: fix syntax error because of missing semicolon

For some asynchronous operations, we build a chain of callbacks to execute when the operation is done. These callbacks are held in $after, and a new callback can be added by appending to $after. Once the operation is done, $after is executed as a script.

But if we don't append a semi-colon after the procedure calls, they will appear to Tcl as arguments to the previous procedure's arguments. So, for example, if $after is "foo", and we just append "bar", then $after becomes "foo bar", and bar will be treated as an argument to foo. If foo does not accept any optional arguments, it would result in Tcl throwing an error. If instead we do append a semi-colon, $after will look like "foo;bar;", and these will be treated as two separate procedure calls.

Before d9c6469 (git-gui: update status bar to track operations, 2019-12-01), this problem was masked because ui_ready/ui_status did accept an optional argument. In d9c6469, ui_ready stopped accepting an optional argument, and this error started showing up.

Another instance of this problem is when a call to ui_status without a trailing semicolon. ui_status never accepted an optional argument to begin with, but the issue never managed to surface.

So, fix these errors by making sure we always append a semi-colon after procedure calls when multiple callbacks are involved in $after.

  @@ -366,7 +366,7 @@ proc add_helper {txt paths} {
   		update_index \
   			$txt \
   			$path_list \
  -			[concat $after {ui_status [mc "Ready to commit."]}]
  +			[concat $after {ui_status [mc "Ready to commit."];}]
   	}
   }

Regards,
Pratyush Yadav