From f8fc5190eeb31b74a5606dd2c381e04aab2c342e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Guillermo=20Vay=C3=A1?= <guillermo.vaya@mattermost.com>
Date: Tue, 29 Jun 2021 19:37:15 +0200
Subject: [PATCH] [MM-36481] Fix emoji regex to support thumbsup (#17846)

---
 app/slashcommands/command_custom_status.go |  2 +-
 model/emoji.go                             | 10 +--
 model/emoji_test.go                        |  3 +
 model/utils.go                             |  6 ++
 model/utils_test.go                        | 78 ++++++++++++++++++++++
 5 files changed, 90 insertions(+), 9 deletions(-)

diff --git a/app/slashcommands/command_custom_status.go b/app/slashcommands/command_custom_status.go
index 56839a030e..b2c1e6097a 100644
--- a/app/slashcommands/command_custom_status.go
+++ b/app/slashcommands/command_custom_status.go
@@ -81,7 +81,7 @@ func GetCustomStatus(message string) *model.CustomStatus {
 		Text:  message,
 	}
 
-	firstEmojiLocations := model.ALL_EMOJI_PATTERN.FindIndex([]byte(message))
+	firstEmojiLocations := model.EMOJI_PATTERN.FindIndex([]byte(message))
 	if len(firstEmojiLocations) > 0 && firstEmojiLocations[0] == 0 {
 		// emoji found at starting index
 		customStatus.Emoji = message[firstEmojiLocations[0]+1 : firstEmojiLocations[1]-1]
diff --git a/model/emoji.go b/model/emoji.go
index bc9b23b891..f990c670d6 100644
--- a/model/emoji.go
+++ b/model/emoji.go
@@ -16,13 +16,7 @@ const (
 	EMOJI_SORT_BY_NAME    = "name"
 )
 
-var EMOJI_PATTERN = regexp.MustCompile(`:[a-zA-Z0-9_-]+:`)
-
-// ALL_EMOJI_PATTERN is same as the EMOJI_PATTERN except for allowing a '+' character.
-// This is to allow the system emoji :+1: to be matched.
-// We kept a separate variable to avoid renaming help texts for custom emoji's.
-// TODO: Merge ALL_EMOJI_PATTERN with EMOJI_PATTERN after updating custom emoji help texts
-var ALL_EMOJI_PATTERN = regexp.MustCompile(`:[a-zA-Z0-9_+-]+:`)
+var EMOJI_PATTERN = regexp.MustCompile(`:[a-zA-Z0-9_+-]+:`)
 
 var ReverseSystemEmojisMap = makeReverseEmojiMap()
 
@@ -86,7 +80,7 @@ func (emoji *Emoji) IsValid() *AppError {
 }
 
 func IsValidEmojiName(name string) *AppError {
-	if name == "" || len(name) > EMOJI_NAME_MAX_LENGTH || !IsValidAlphaNumHyphenUnderscore(name, false) || inSystemEmoji(name) {
+	if name == "" || len(name) > EMOJI_NAME_MAX_LENGTH || !IsValidAlphaNumHyphenUnderscorePlus(name) || inSystemEmoji(name) {
 		return NewAppError("Emoji.IsValid", "model.emoji.name.app_error", nil, "", http.StatusBadRequest)
 	}
 
diff --git a/model/emoji_test.go b/model/emoji_test.go
index 1600113258..763b7aa2e7 100644
--- a/model/emoji_test.go
+++ b/model/emoji_test.go
@@ -50,6 +50,9 @@ func TestEmojiIsValid(t *testing.T) {
 	emoji.Name = "name-"
 	require.Nil(t, emoji.IsValid())
 
+	emoji.Name = "name+"
+	require.Nil(t, emoji.IsValid())
+
 	emoji.Name = "name_"
 	require.Nil(t, emoji.IsValid())
 
diff --git a/model/utils.go b/model/utils.go
index 903bc0d0d3..0c5a272c26 100644
--- a/model/utils.go
+++ b/model/utils.go
@@ -438,6 +438,12 @@ func IsValidAlphaNumHyphenUnderscore(s string, withFormat bool) bool {
 	return validSimpleAlphaNumHyphenUnderscore.MatchString(s)
 }
 
+func IsValidAlphaNumHyphenUnderscorePlus(s string) bool {
+
+	validSimpleAlphaNumHyphenUnderscorePlus := regexp.MustCompile(`^[a-zA-Z0-9+_-]+$`)
+	return validSimpleAlphaNumHyphenUnderscorePlus.MatchString(s)
+}
+
 func Etag(parts ...interface{}) string {
 
 	etag := CurrentVersion
diff --git a/model/utils_test.go b/model/utils_test.go
index 059910fd9f..acb466d610 100644
--- a/model/utils_test.go
+++ b/model/utils_test.go
@@ -476,6 +476,84 @@ func TestIsValidAlphaNumHyphenUnderscore(t *testing.T) {
 	}
 }
 
+func TestIsValidAlphaNumHyphenUnderscorePlus(t *testing.T) {
+	cases := []struct {
+		Input  string
+		Result bool
+	}{
+		{
+			Input:  "test",
+			Result: true,
+		},
+		{
+			Input:  "test+name",
+			Result: true,
+		},
+		{
+			Input:  "test+-name",
+			Result: true,
+		},
+		{
+			Input:  "test_+name",
+			Result: true,
+		},
+		{
+			Input:  "test++name",
+			Result: true,
+		},
+		{
+			Input:  "test_-name",
+			Result: true,
+		},
+		{
+			Input:  "-",
+			Result: true,
+		},
+		{
+			Input:  "_",
+			Result: true,
+		},
+		{
+			Input:  "+",
+			Result: true,
+		},
+		{
+			Input:  "test+",
+			Result: true,
+		},
+		{
+			Input:  "test++",
+			Result: true,
+		},
+		{
+			Input:  "test--",
+			Result: true,
+		},
+		{
+			Input:  "test__",
+			Result: true,
+		},
+		{
+			Input:  ".",
+			Result: false,
+		},
+
+		{
+			Input:  "test,",
+			Result: false,
+		},
+		{
+			Input:  "test:name",
+			Result: false,
+		},
+	}
+
+	for _, tc := range cases {
+		actual := IsValidAlphaNumHyphenUnderscorePlus(tc.Input)
+		require.Equalf(t, actual, tc.Result, "case: '%v'\tshould returned: %#v", tc.Input, tc.Result)
+	}
+}
+
 func TestIsValidId(t *testing.T) {
 	cases := []struct {
 		Input  string