Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

git-gui/lib/date.tcl

@@ -0,0 +1,53 @@
+# git-gui date processing support
+# Copyright (C) 2007 Shawn Pearce
+
+set git_month(Jan)  1
+set git_month(Feb)  2
+set git_month(Mar)  3
+set git_month(Apr)  4
+set git_month(May)  5
+set git_month(Jun)  6
+set git_month(Jul)  7
+set git_month(Aug)  8
+set git_month(Sep)  9
+set git_month(Oct) 10
+set git_month(Nov) 11
+set git_month(Dec) 12
+
+proc parse_git_date {s} {
+	if {$s eq {}} {
+		return {}
+	}
+
+	if {![regexp \
+		{^... (...) (\d{1,2}) (\d\d):(\d\d):(\d\d) (\d{4}) ([+-]?)(\d\d)(\d\d)$} $s s \
+		month day hr mm ss yr ew tz_h tz_m]} {
+		error [mc "Invalid date from Git: %s" $s]
+	}
+
+	set s [clock scan [format {%4.4i%2.2i%2.2iT%2s%2s%2s} \
+			$yr $::git_month($month) $day \
+			$hr $mm $ss] \
+			-gmt 1]
+
+	regsub ^0 $tz_h {} tz_h
+	regsub ^0 $tz_m {} tz_m
+	switch -- $ew {
+	-  {set ew +}
+	+  {set ew -}
+	{} {set ew -}
+	}
+
+	return [expr "$s $ew ($tz_h * 3600 + $tz_m * 60)"]
+}
+
+proc format_date {s} {
+	if {$s eq {}} {
+		return {}
+	}
+	return [clock format $s -format {%a %b %e %H:%M:%S %Y}]
+}
+
+proc reformat_date {s} {
+	return [format_date [parse_git_date $s]]
+}