merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 403 insertions, 134 deletions

diff --git a/third_party/git/git-gui/lib/index.tcl b/third_party/git/git-gui/lib/index.tcl
index b588db11d9fc..d2ec24bd80e1 100644
--- a/third_party/git/git-gui/lib/index.tcl
+++ b/third_party/git/git-gui/lib/index.tcl
@@ -7,67 +7,74 @@ proc _delete_indexlock {} {
 	}
 }
 
-proc _close_updateindex {fd after} {
-	global use_ttk NS
-	fconfigure $fd -blocking 1
-	if {[catch {close $fd} err]} {
-		set w .indexfried
-		Dialog $w
-		wm withdraw $w
-		wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
-		wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
-		set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
-		text $w.msg -yscrollcommand [list $w.vs set] \
-			-width [string length $s] -relief flat \
-			-borderwidth 0 -highlightthickness 0 \
-			-background [get_bg_color $w]
-		$w.msg tag configure bold -font font_uibold -justify center
-		${NS}::scrollbar $w.vs -command [list $w.msg yview]
-		$w.msg insert end $s bold \n\n$err {}
-		$w.msg configure -state disabled
-
-		${NS}::button $w.continue \
-			-text [mc "Continue"] \
-			-command [list destroy $w]
-		${NS}::button $w.unlock \
-			-text [mc "Unlock Index"] \
-			-command "destroy $w; _delete_indexlock"
-		grid $w.msg - $w.vs -sticky news
-		grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
-		grid columnconfigure $w 0 -weight 1
-		grid rowconfigure $w 0 -weight 1
-
-		wm protocol $w WM_DELETE_WINDOW update
-		bind $w.continue <Visibility> "
-			grab $w
-			focus %W
-		"
-		wm deiconify $w
-		tkwait window $w
-
-		$::main_status stop
+proc close_and_unlock_index {fd after} {
+	if {![catch {_close_updateindex $fd} err]} {
 		unlock_index
-		rescan $after 0
-		return
+		uplevel #0 $after
+	} else {
+		rescan_on_error $err $after
 	}
+}
 
-	$::main_status stop
+proc _close_updateindex {fd} {
+	fconfigure $fd -blocking 1
+	close $fd
+}
+
+proc rescan_on_error {err {after {}}} {
+	global use_ttk NS
+
+	set w .indexfried
+	Dialog $w
+	wm withdraw $w
+	wm title $w [strcat "[appname] ([reponame]): " [mc "Index Error"]]
+	wm geometry $w "+[winfo rootx .]+[winfo rooty .]"
+	set s [mc "Updating the Git index failed.  A rescan will be automatically started to resynchronize git-gui."]
+	text $w.msg -yscrollcommand [list $w.vs set] \
+		-width [string length $s] -relief flat \
+		-borderwidth 0 -highlightthickness 0 \
+		-background [get_bg_color $w]
+	$w.msg tag configure bold -font font_uibold -justify center
+	${NS}::scrollbar $w.vs -command [list $w.msg yview]
+	$w.msg insert end $s bold \n\n$err {}
+	$w.msg configure -state disabled
+
+	${NS}::button $w.continue \
+		-text [mc "Continue"] \
+		-command [list destroy $w]
+	${NS}::button $w.unlock \
+		-text [mc "Unlock Index"] \
+		-command "destroy $w; _delete_indexlock"
+	grid $w.msg - $w.vs -sticky news
+	grid $w.unlock $w.continue - -sticky se -padx 2 -pady 2
+	grid columnconfigure $w 0 -weight 1
+	grid rowconfigure $w 0 -weight 1
+
+	wm protocol $w WM_DELETE_WINDOW update
+	bind $w.continue <Visibility> "
+		grab $w
+		focus %W
+	"
+	wm deiconify $w
+	tkwait window $w
+
+	$::main_status stop_all
 	unlock_index
-	uplevel #0 $after
+	rescan [concat $after {ui_ready;}] 0
 }
 
-proc update_indexinfo {msg pathList after} {
+proc update_indexinfo {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index -z --index-info]
 	fconfigure $fd \
 		-blocking 0 \
@@ -78,26 +85,29 @@ proc update_indexinfo {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_indexinfo \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_indexinfo {fd pathList totalCnt batch after} {
+proc write_update_indexinfo {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
-		_close_updateindex $fd $after
+	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
+		close_and_unlock_index $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		set s $file_states($path)
@@ -119,21 +129,21 @@ proc write_update_indexinfo {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc update_index {msg pathList after} {
+proc update_index {msg path_list after} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write update-index --add --remove -z --stdin]
 	fconfigure $fd \
 		-blocking 0 \
@@ -144,26 +154,29 @@ proc update_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_update_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
 		]
 }
 
-proc write_update_index {fd pathList totalCnt batch after} {
+proc write_update_index {fd path_list total_cnt batch status_bar_operation \
+	after} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
-		_close_updateindex $fd $after
+	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
+		close_and_unlock_index $fd $after
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -190,21 +203,21 @@ proc write_update_index {fd pathList totalCnt batch after} {
 		display_file $path $new
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
-proc checkout_index {msg pathList after} {
+proc checkout_index {msg path_list after capture_error} {
 	global update_index_cp
 
 	if {![lock_index update]} return
 
 	set update_index_cp 0
-	set pathList [lsort $pathList]
-	set totalCnt [llength $pathList]
-	set batch [expr {int($totalCnt * .01) + 1}]
+	set path_list [lsort $path_list]
+	set total_cnt [llength $path_list]
+	set batch [expr {int($total_cnt * .01) + 1}]
 	if {$batch > 25} {set batch 25}
 
-	$::main_status start $msg [mc "files"]
+	set status_bar_operation [$::main_status start $msg [mc "files"]]
 	set fd [git_write checkout-index \
 		--index \
 		--quiet \
@@ -221,26 +234,45 @@ proc checkout_index {msg pathList after} {
 	fileevent $fd writable [list \
 		write_checkout_index \
 		$fd \
-		$pathList \
-		$totalCnt \
+		$path_list \
+		$total_cnt \
 		$batch \
+		$status_bar_operation \
 		$after \
+		$capture_error \
 		]
 }
 
-proc write_checkout_index {fd pathList totalCnt batch after} {
+proc write_checkout_index {fd path_list total_cnt batch status_bar_operation \
+	after capture_error} {
 	global update_index_cp
 	global file_states current_diff_path
 
-	if {$update_index_cp >= $totalCnt} {
-		_close_updateindex $fd $after
+	if {$update_index_cp >= $total_cnt} {
+		$status_bar_operation stop
+
+		# We do not unlock the index directly here because this
+		# operation expects to potentially run in parallel with file
+		# deletions scheduled by revert_helper. We're done with the
+		# update index, so we close it, but actually unlocking the index
+		# and dealing with potential errors is deferred to the chord
+		# body that runs when all async operations are completed.
+		#
+		# (See after_chord in revert_helper.)
+
+		if {[catch {_close_updateindex $fd} err]} {
+			uplevel #0 $capture_error [list $err]
+		}
+
+		uplevel #0 $after
+
 		return
 	}
 
 	for {set i $batch} \
-		{$update_index_cp < $totalCnt && $i > 0} \
+		{$update_index_cp < $total_cnt && $i > 0} \
 		{incr i -1} {
-		set path [lindex $pathList $update_index_cp]
+		set path [lindex $path_list $update_index_cp]
 		incr update_index_cp
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
@@ -253,7 +285,7 @@ proc write_checkout_index {fd pathList totalCnt batch after} {
 		}
 	}
 
-	$::main_status update $update_index_cp $totalCnt
+	$status_bar_operation update $update_index_cp $total_cnt
 }
 
 proc unstage_helper {txt paths} {
@@ -261,7 +293,7 @@ proc unstage_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -269,20 +301,20 @@ proc unstage_helper {txt paths} {
 		M? -
 		T? -
 		D? {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_indexinfo \
 			$txt \
-			$pathList \
-			[concat $after [list ui_ready]]
+			$path_list \
+			[concat $after {ui_ready;}]
 	}
 }
 
@@ -305,7 +337,7 @@ proc add_helper {txt paths} {
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
+	set path_list [list]
 	set after {}
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
@@ -321,20 +353,20 @@ proc add_helper {txt paths} {
 		?M -
 		?D -
 		?T {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
 				set after {reshow_diff;}
 			}
 		}
 		}
 	}
-	if {$pathList eq {}} {
+	if {$path_list eq {}} {
 		unlock_index
 	} else {
 		update_index \
 			$txt \
-			$pathList \
-			[concat $after {ui_status [mc "Ready to commit."]}]
+			$path_list \
+			[concat $after {ui_status [mc "Ready to commit."];}]
 	}
 }
 
@@ -388,66 +420,303 @@ proc do_add_all {} {
 	add_helper [mc "Adding all changed files"] $paths
 }
 
+# Copied from TclLib package "lambda".
+proc lambda {arguments body args} {
+	return [list ::apply [list $arguments $body] {*}$args]
+}
+
 proc revert_helper {txt paths} {
 	global file_states current_diff_path
 
 	if {![lock_index begin-update]} return
 
-	set pathList [list]
-	set after {}
+	# Common "after" functionality that waits until multiple asynchronous
+	# operations are complete (by waiting for them to activate their notes
+	# on the chord).
+	#
+	# The asynchronous operations are each indicated below by a comment
+	# before the code block that starts the async operation.
+	set after_chord [SimpleChord::new {
+		if {[string trim $err] != ""} {
+			rescan_on_error $err
+		} else {
+			unlock_index
+			if {$should_reshow_diff} { reshow_diff }
+			ui_ready
+		}
+	}]
+
+	$after_chord eval { set should_reshow_diff 0 }
+
+	# This function captures an error for processing when after_chord is
+	# completed. (The chord is curried into the lambda function.)
+	set capture_error [lambda \
+		{chord error} \
+		{ $chord eval [list set err $error] } \
+		$after_chord]
+
+	# We don't know how many notes we're going to create (it's dynamic based
+	# on conditional paths below), so create a common note that will delay
+	# the chord's completion until we activate it, and then activate it
+	# after all the other notes have been created.
+	set after_common_note [$after_chord add_note]
+
+	set path_list [list]
+	set untracked_list [list]
+
 	foreach path $paths {
 		switch -glob -- [lindex $file_states($path) 0] {
 		U? {continue}
+		?O {
+			lappend untracked_list $path
+		}
 		?M -
 		?T -
 		?D {
-			lappend pathList $path
+			lappend path_list $path
 			if {$path eq $current_diff_path} {
-				set after {reshow_diff;}
+				$after_chord eval { set should_reshow_diff 1 }
 			}
 		}
 		}
 	}
 
+	set path_cnt [llength $path_list]
+	set untracked_cnt [llength $untracked_list]
+
+	# Asynchronous operation: revert changes by checking them out afresh
+	# from the index.
+	if {$path_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages. Previously, the
+		# code used "Revert changes in" for both, but that can't work
+		# in languages where 'in' must be combined with word from
+		# rest of string (in different way for both cases of course).
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$path_cnt == 1} {
+			set query [mc \
+				"Revert changes in file %s?" \
+				[short_path [lindex $path_list]] \
+				]
+		} else {
+			set query [mc \
+				"Revert changes in these %i files?" \
+				$path_cnt]
+		}
 
-	# Split question between singular and plural cases, because
-	# such distinction is needed in some languages. Previously, the
-	# code used "Revert changes in" for both, but that can't work
-	# in languages where 'in' must be combined with word from
-	# rest of string (in different way for both cases of course).
-	#
-	# FIXME: Unfortunately, even that isn't enough in some languages
-	# as they have quite complex plural-form rules. Unfortunately,
-	# msgcat doesn't seem to support that kind of string translation.
-	#
-	set n [llength $pathList]
-	if {$n == 0} {
-		unlock_index
-		return
-	} elseif {$n == 1} {
-		set query [mc "Revert changes in file %s?" [short_path [lindex $pathList]]]
-	} else {
-		set query [mc "Revert changes in these %i files?" $n]
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Any unstaged changes will be permanently lost by the revert."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Revert Changes"] \
+			]
+
+		if {$reply == 1} {
+			set note [$after_chord add_note]
+			checkout_index \
+				$txt \
+				$path_list \
+				[list $note activate] \
+				$capture_error
+		}
+	}
+
+	# Asynchronous operation: Deletion of untracked files.
+	if {$untracked_cnt > 0} {
+		# Split question between singular and plural cases, because
+		# such distinction is needed in some languages.
+		#
+		# FIXME: Unfortunately, even that isn't enough in some languages
+		# as they have quite complex plural-form rules. Unfortunately,
+		# msgcat doesn't seem to support that kind of string
+		# translation.
+		#
+		if {$untracked_cnt == 1} {
+			set query [mc \
+				"Delete untracked file %s?" \
+				[short_path [lindex $untracked_list]] \
+				]
+		} else {
+			set query [mc \
+				"Delete these %i untracked files?" \
+				$untracked_cnt \
+				]
+		}
+
+		set reply [tk_dialog \
+			.confirm_revert \
+			"[appname] ([reponame])" \
+			"$query
+
+[mc "Files will be permanently deleted."]" \
+			question \
+			1 \
+			[mc "Do Nothing"] \
+			[mc "Delete Files"] \
+			]
+
+		if {$reply == 1} {
+			$after_chord eval { set should_reshow_diff 1 }
+
+			set note [$after_chord add_note]
+			delete_files $untracked_list [list $note activate]
+		}
 	}
 
-	set reply [tk_dialog \
-		.confirm_revert \
-		"[appname] ([reponame])" \
-		"$query
+	# Activate the common note. If no other notes were created, this
+	# completes the chord. If other notes were created, then this common
+	# note prevents a race condition where the chord might complete early.
+	$after_common_note activate
+}
 
-[mc "Any unstaged changes will be permanently lost by the revert."]" \
-		question \
-		1 \
-		[mc "Do Nothing"] \
-		[mc "Revert Changes"] \
-		]
-	if {$reply == 1} {
-		checkout_index \
-			$txt \
-			$pathList \
-			[concat $after [list ui_ready]]
+# Delete all of the specified files, performing deletion in batches to allow the
+# UI to remain responsive and updated.
+proc delete_files {path_list after} {
+	# Enable progress bar status updates
+	set status_bar_operation [$::main_status \
+		start \
+		[mc "Deleting"] \
+		[mc "files"]]
+
+	set path_index 0
+	set deletion_errors [list]
+	set batch_size 50
+
+	delete_helper \
+		$path_list \
+		$path_index \
+		$deletion_errors \
+		$batch_size \
+		$status_bar_operation \
+		$after
+}
+
+# Helper function to delete a list of files in batches. Each call deletes one
+# batch of files, and then schedules a call for the next batch after any UI
+# messages have been processed.
+proc delete_helper {path_list path_index deletion_errors batch_size \
+	status_bar_operation after} {
+	global file_states
+
+	set path_cnt [llength $path_list]
+
+	set batch_remaining $batch_size
+
+	while {$batch_remaining > 0} {
+		if {$path_index >= $path_cnt} { break }
+
+		set path [lindex $path_list $path_index]
+
+		set deletion_failed [catch {file delete -- $path} deletion_error]
+
+		if {$deletion_failed} {
+			lappend deletion_errors [list "$deletion_error"]
+		} else {
+			remove_empty_directories [file dirname $path]
+
+			# Don't assume the deletion worked. Remove the file from
+			# the UI, but only if it no longer exists.
+			if {![path_exists $path]} {
+				unset file_states($path)
+				display_file $path __
+			}
+		}
+
+		incr path_index 1
+		incr batch_remaining -1
+	}
+
+	# Update the progress bar to indicate that this batch has been
+	# completed. The update will be visible when this procedure returns
+	# and allows the UI thread to process messages.
+	$status_bar_operation update $path_index $path_cnt
+
+	if {$path_index < $path_cnt} {
+		# The Tcler's Wiki lists this as the best practice for keeping
+		# a UI active and processing messages during a long-running
+		# operation.
+
+		after idle [list after 0 [list \
+			delete_helper \
+			$path_list \
+			$path_index \
+			$deletion_errors \
+			$batch_size \
+			$status_bar_operation \
+			$after
+			]]
 	} else {
-		unlock_index
+		# Finish the status bar operation.
+		$status_bar_operation stop
+
+		# Report error, if any, based on how many deletions failed.
+		set deletion_error_cnt [llength $deletion_errors]
+
+		if {($deletion_error_cnt > 0)
+		 && ($deletion_error_cnt <= [MAX_VERBOSE_FILES_IN_DELETION_ERROR])} {
+			set error_text [mc "Encountered errors deleting files:\n"]
+
+			foreach deletion_error $deletion_errors {
+				append error_text "* [lindex $deletion_error 0]\n"
+			}
+
+			error_popup $error_text
+		} elseif {$deletion_error_cnt == $path_cnt} {
+			error_popup [mc \
+				"None of the %d selected files could be deleted." \
+				$path_cnt \
+				]
+		} elseif {$deletion_error_cnt > 1} {
+			error_popup [mc \
+				"%d of the %d selected files could not be deleted." \
+				$deletion_error_cnt \
+				$path_cnt \
+				]
+		}
+
+		uplevel #0 $after
+	}
+}
+
+proc MAX_VERBOSE_FILES_IN_DELETION_ERROR {} { return 10; }
+
+# This function is from the TCL documentation:
+#
+#   https://wiki.tcl-lang.org/page/file+exists
+#
+# [file exists] returns false if the path does exist but is a symlink to a path
+# that doesn't exist. This proc returns true if the path exists, regardless of
+# whether it is a symlink and whether it is broken.
+proc path_exists {name} {
+	expr {![catch {file lstat $name finfo}]}
+}
+
+# Remove as many empty directories as we can starting at the specified path,
+# walking up the directory tree. If we encounter a directory that is not
+# empty, or if a directory deletion fails, then we stop the operation and
+# return to the caller. Even if this procedure fails to delete any
+# directories at all, it does not report failure.
+proc remove_empty_directories {directory_path} {
+	set parent_path [file dirname $directory_path]
+
+	while {$parent_path != $directory_path} {
+		set contents [glob -nocomplain -dir $directory_path *]
+
+		if {[llength $contents] > 0} { break }
+		if {[catch {file delete -- $directory_path}]} { break }
+
+		set directory_path $parent_path
+		set parent_path [file dirname $directory_path]
 	}
 }
 
@@ -466,19 +735,19 @@ proc do_revert_selection {} {
 }
 
 proc do_select_commit_type {} {
-	global commit_type selected_commit_type
+	global commit_type commit_type_is_amend
 
-	if {$selected_commit_type eq {new}
+	if {$commit_type_is_amend == 0
 		&& [string match amend* $commit_type]} {
 		create_new_commit
-	} elseif {$selected_commit_type eq {amend}
+	} elseif {$commit_type_is_amend == 1
 		&& ![string match amend* $commit_type]} {
 		load_last_commit
 
 		# The amend request was rejected...
 		#
 		if {![string match amend* $commit_type]} {
-			set selected_commit_type new
+			set commit_type_is_amend 0
 		}
 	}
 }