MDEV-17950 SHOW GRANTS FOR does not work for a user identified with non-existing plugin

Revert the side effect of 7c40996cc866.
Do not convert password hash to its binary representation when a user
entry is loaded. Do it lazily on the first authenticatation attempt.

As a collateral - force all authentication plugins to follow the
protocol and read_packet at least once before accessing info->username
(username is not available before first client handshake packet is read).

Fix PAM and GSSAPI plugins to behave.

1 files changed, 9 insertions, 13 deletions

diff --git a/mysql-test/main/grant5.result b/mysql-test/main/grant5.result
index 5bf7b2d1934..c35e8201582 100644
--- a/mysql-test/main/grant5.result
+++ b/mysql-test/main/grant5.result
@@ -59,12 +59,9 @@ update mysql.global_priv set priv=json_set(priv, '$.authentication_string', 'bad
 update mysql.global_priv set priv=json_set(priv, '$.authentication_string', 'bad') where user='u5';
 update mysql.global_priv set priv=json_set(priv, '$.plugin', 'nonexistent') where user='u8';
 flush privileges;
-Warnings:
-Error	1372	Password hash should be a 41-digit hexadecimal number
-Error	1372	Password hash should be a 16-digit hexadecimal number
-Warning	1524	Plugin 'nonexistent' is not loaded
 show create user u1@h;
-ERROR 28000: Can't find any matching row in the user table
+CREATE USER for u1@h
+CREATE USER 'u1'@'h' IDENTIFIED BY PASSWORD 'bad'
 show create user u2@h;
 CREATE USER for u2@h
 CREATE USER 'u2'@'h' IDENTIFIED BY PASSWORD '*975B2CD4FF9AE554FE8AD33168FBFC326D2021DD'
@@ -75,7 +72,8 @@ show create user u4@h;
 CREATE USER for u4@h
 CREATE USER 'u4'@'h' IDENTIFIED BY PASSWORD '*975B2CD4FF9AE554FE8AD33168FBFC326D2021DD'
 show create user u5@h;
-ERROR 28000: Can't find any matching row in the user table
+CREATE USER for u5@h
+CREATE USER 'u5'@'h' IDENTIFIED BY PASSWORD 'bad'
 show create user u6@h;
 CREATE USER for u6@h
 CREATE USER 'u6'@'h' IDENTIFIED BY PASSWORD '78a302dd267f6044'
@@ -83,26 +81,24 @@ show create user u7@h;
 CREATE USER for u7@h
 CREATE USER 'u7'@'h' IDENTIFIED BY PASSWORD '78a302dd267f6044'
 show create user u8@h;
-ERROR 28000: Can't find any matching row in the user table
+CREATE USER for u8@h
+CREATE USER 'u8'@'h' IDENTIFIED VIA nonexistent USING '78a302dd267f6044'
 grant select on *.* to u1@h;
-ERROR 28000: Can't find any matching row in the user table
 grant select on *.* to u2@h;
 grant select on *.* to u3@h;
 grant select on *.* to u4@h;
 grant select on *.* to u5@h;
-ERROR 28000: Can't find any matching row in the user table
 grant select on *.* to u6@h;
 grant select on *.* to u7@h;
 grant select on *.* to u8@h;
-ERROR 28000: Can't find any matching row in the user table
 select user,select_priv,plugin,authentication_string from mysql.user where user like 'u_';
 User	Select_priv	plugin	authentication_string
-u1	N	mysql_native_password	bad
+u1	Y	mysql_native_password	bad
 u2	Y	mysql_native_password	*975B2CD4FF9AE554FE8AD33168FBFC326D2021DD
 u3	Y	mysql_native_password	*975B2CD4FF9AE554FE8AD33168FBFC326D2021DD
 u4	Y	mysql_native_password	*975B2CD4FF9AE554FE8AD33168FBFC326D2021DD
-u5	N	mysql_old_password	bad
+u5	Y	mysql_old_password	bad
 u6	Y	mysql_old_password	78a302dd267f6044
 u7	Y	mysql_old_password	78a302dd267f6044
-u8	N	nonexistent	78a302dd267f6044
+u8	Y	nonexistent	78a302dd267f6044
 drop user u1@h, u2@h, u3@h, u4@h, u5@h, u6@h, u7@h, u8@h;