From 667afd9dca52123837af67c54f8866217368bd30 Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Fri, 24 Jul 2020 15:24:33 +0800
Subject: [PATCH] types: fix STR_TO_DATE handling for %h, %r (#18171) (#18428)
 (#18725)

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
---
 types/format_test.go | 13 +++++++------
 types/time.go        |  9 +++++++++
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/types/format_test.go b/types/format_test.go
index 642713476e833..91dc4f8344032 100644
--- a/types/format_test.go
+++ b/types/format_test.go
@@ -89,9 +89,11 @@ func (s *testTimeSuite) TestStrToDate(c *C) {
 		{`a09:30:17`, `a%h:%i:%s`, types.FromDate(0, 0, 0, 9, 30, 17, 0)},
 		{`09:30:17a`, `%h:%i:%s`, types.FromDate(0, 0, 0, 9, 30, 17, 0)},
 		{`abc`, `abc`, types.ZeroTime},
+		{`12:43:24`, `%h:%i:%s`, types.FromDate(0, 0, 0, 0, 43, 24, 0)},
 		{`09`, `%m`, types.FromDate(0, 9, 0, 0, 0, 0, 0)},
 		{`09`, `%s`, types.FromDate(0, 0, 0, 0, 0, 9, 0)},
-		{`12:43:24 AM`, `%r`, types.FromDate(0, 0, 0, 12, 43, 24, 0)},
+		{`12:43:24 AM`, `%r`, types.FromDate(0, 0, 0, 0, 43, 24, 0)},
+		{`12:43:24 PM`, `%r`, types.FromDate(0, 0, 0, 12, 43, 24, 0)},
 		{`11:43:24 PM`, `%r`, types.FromDate(0, 0, 0, 23, 43, 24, 0)},
 		{`00:12:13`, `%T`, types.FromDate(0, 0, 0, 0, 12, 13, 0)},
 		{`23:59:59`, `%T`, types.FromDate(0, 0, 0, 23, 59, 59, 0)},
@@ -129,9 +131,8 @@ func (s *testTimeSuite) TestStrToDate(c *C) {
 	}{
 		{`04/31/2004`, `%m/%d/%Y`},
 		{`a09:30:17`, `%h:%i:%s`}, // format mismatch
-		{`12:43:24 PM`, `%r`},
-		{`12:43:24`, `%r`}, // no PM or AM followed
-		{`23:60:12`, `%T`}, // invalid minute
+		{`12:43:24`, `%r`},        // no PM or AM followed
+		{`23:60:12`, `%T`},        // invalid minute
 		{`18`, `%l`},
 		{`00:21:22 AM`, `%h:%i:%s %p`},
 		{`100/10/22`, `%y/%m/%d`},
@@ -139,8 +140,8 @@ func (s *testTimeSuite) TestStrToDate(c *C) {
 		{"2010-11-12 13 am", `%Y-%m-%d %h %p`},
 		{"2010-11-12 0 am", `%Y-%m-%d %h %p`},
 	}
-	for _, tt := range errTests {
+	for i, tt := range errTests {
 		var t types.Time
-		c.Assert(t.StrToDate(sc, tt.input, tt.format), IsFalse)
+		c.Assert(t.StrToDate(sc, tt.input, tt.format), IsFalse, Commentf("no.%d failed", i))
 	}
 }
diff --git a/types/time.go b/types/time.go
index ab8fa43beab0b..9a874597db4c5 100644
--- a/types/time.go
+++ b/types/time.go
@@ -2190,6 +2190,10 @@ func mysqlTimeFix(t *MysqlTime, ctx map[string]int) error {
 		if valueAMorPm == constForPM {
 			t.hour += 12
 		}
+	} else {
+		if _, ok := ctx["%h"]; ok && t.Hour() == 12 {
+			t.hour = 0
+		}
 	}
 	return nil
 }
@@ -2405,6 +2409,10 @@ func time12Hour(t *MysqlTime, input string, ctx map[string]int) (string, bool) {
 	if !succ || hour > 12 || hour == 0 || input[2] != ':' {
 		return input, false
 	}
+	// 12:34:56 AM -> 00:34:56
+	if hour == 12 {
+		hour = 0
+	}
 
 	minute, succ := parseDigits(input[3:], 2)
 	if !succ || minute > 59 || input[5] != ':' {
@@ -2550,6 +2558,7 @@ func hour12Numeric(t *MysqlTime, input string, ctx map[string]int) (string, bool
 		return input, false
 	}
 	t.hour = v
+	ctx["%h"] = v
 	return input[length:], true
 }