Merge branch 'ms/commit-template'

Teach git-gui to read the commit message template and pre-populate it in
the commit message buffer.

* ms/commit-template:
  git-gui: use commit message template
  git-gui: Only touch GITGUI_MSG when needed

Author: prati0100

git-gui.sh

@@ -1482,6 +1482,7 @@ proc rescan {after {honor_trustmtime 1}} {
 		} elseif {[run_prepare_commit_msg_hook]} {
 		} elseif {[load_message MERGE_MSG]} {
 		} elseif {[load_message SQUASH_MSG]} {
+		} elseif {[load_message [get_config commit.template]]} {
 		}
 		$ui_comm edit reset
 		$ui_comm edit modified false
@@ -1616,6 +1617,12 @@ proc run_prepare_commit_msg_hook {} {
 		fconfigure $fd_sm -encoding utf-8
 		puts -nonewline $fd_pcm [read $fd_sm]
 		close $fd_sm
+	} elseif {[file isfile [get_config commit.template]]} {
+		set pcm_source "template"
+		set fd_sm [open [get_config commit.template] r]
+		fconfigure $fd_sm -encoding utf-8
+		puts -nonewline $fd_pcm [read $fd_sm]
+		close $fd_sm
 	} else {
 		set pcm_source ""
 	}
@@ -2305,11 +2312,10 @@ proc do_quit {{rc {1}}} {
 		if {$GITGUI_BCK_exists && ![$ui_comm edit modified]} {
 			file rename -force [gitdir GITGUI_BCK] $save
 			set GITGUI_BCK_exists 0
-		} else {
+		} elseif {[$ui_comm edit modified]} {
 			set msg [string trim [$ui_comm get 0.0 end]]
 			regsub -all -line {[ \r\t]+$} $msg {} msg
-			if {(![string match amend* $commit_type]
-				|| [$ui_comm edit modified])
+			if {![string match amend* $commit_type]
 				&& $msg ne {}} {
 				catch {
 					set fd [open $save w]

lib/commit.tcl

@@ -456,6 +456,7 @@ A rescan will be automatically started now.
 	}
 
 	$ui_comm delete 0.0 end
+	load_message [get_config commit.template]
 	$ui_comm edit reset
 	$ui_comm edit modified false
 	if {$::GITGUI_BCK_exists} {