From af3bf39aad8c5ec58a3d8e2f59f4c10aa804d231 Mon Sep 17 00:00:00 2001
From: robot-clickhouse <robot-clickhouse@yandex-team.ru>
Date: Thu, 15 Oct 2020 17:42:24 +0300
Subject: [PATCH] Backport #15982 to 20.9: Fix ambiguity in parsing of settings
 profiles.

---
 src/Parsers/ParserSettingsProfileElement.cpp  | 37 +++++++++++++------
 .../01294_create_settings_profile.reference   |  7 ++++
 .../01294_create_settings_profile.sql         | 15 ++++++++
 3 files changed, 48 insertions(+), 11 deletions(-)

diff --git a/src/Parsers/ParserSettingsProfileElement.cpp b/src/Parsers/ParserSettingsProfileElement.cpp
index f1e66a296e70..d7d982efe236 100644
--- a/src/Parsers/ParserSettingsProfileElement.cpp
+++ b/src/Parsers/ParserSettingsProfileElement.cpp
@@ -6,6 +6,7 @@
 #include <Parsers/ASTLiteral.h>
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/parseIdentifierOrStringLiteral.h>
+#include <boost/algorithm/string/predicate.hpp>
 
 
 namespace DB
@@ -14,8 +15,16 @@ namespace
 {
     bool parseProfileKeyword(IParserBase::Pos & pos, Expected & expected, bool use_inherit_keyword)
     {
-        return ParserKeyword{"PROFILE"}.ignore(pos, expected) ||
-            (use_inherit_keyword && ParserKeyword{"INHERIT"}.ignore(pos, expected));
+        if (ParserKeyword{"PROFILE"}.ignore(pos, expected))
+            return true;
+
+        if (use_inherit_keyword && ParserKeyword{"INHERIT"}.ignore(pos, expected))
+        {
+            ParserKeyword{"PROFILE"}.ignore(pos, expected);
+            return true;
+        }
+
+        return false;
     }
 
 
@@ -137,6 +146,15 @@ namespace
             if (!has_value_or_constraint)
                 return false;
 
+            if (boost::iequals(res_setting_name, "PROFILE") && res_value.isNull() && res_min_value.isNull() && res_max_value.isNull()
+                && res_readonly)
+            {
+                /// Ambiguity: "profile readonly" can be treated either as a profile named "readonly" or
+                /// as a setting named 'profile' with the readonly constraint.
+                /// So we've decided to treat it as a profile named "readonly".
+                return false;
+            }
+
             setting_name = std::move(res_setting_name);
             value = std::move(res_value);
             min_value = std::move(res_min_value);
@@ -163,15 +181,12 @@ namespace
             Field max_value;
             std::optional<bool> readonly;
 
-            if (parseSettingNameWithValueOrConstraints(pos, expected, setting_name, value, min_value, max_value, readonly))
-            {
-            }
-            else if (parseProfileKeyword(pos, expected, use_inherit_keyword) || previous_element_was_parent_profile)
-            {
-                if (!parseProfileNameOrID(pos, expected, id_mode, parent_profile))
-                    return false;
-            }
-            else
+            bool ok = parseSettingNameWithValueOrConstraints(pos, expected, setting_name, value, min_value, max_value, readonly);
+
+            if (!ok && (parseProfileKeyword(pos, expected, use_inherit_keyword) || previous_element_was_parent_profile))
+                ok = parseProfileNameOrID(pos, expected, id_mode, parent_profile);
+
+            if (!ok)
                 return false;
 
             result = std::make_shared<ASTSettingsProfileElement>();
diff --git a/tests/queries/0_stateless/01294_create_settings_profile.reference b/tests/queries/0_stateless/01294_create_settings_profile.reference
index 0780a42ebed7..ab1b3833419f 100644
--- a/tests/queries/0_stateless/01294_create_settings_profile.reference
+++ b/tests/queries/0_stateless/01294_create_settings_profile.reference
@@ -41,6 +41,13 @@ CREATE SETTINGS PROFILE s1_01294 SETTINGS max_memory_usage = 6000000
 CREATE SETTINGS PROFILE s2_01294 SETTINGS max_memory_usage = 6000000 TO r1_01294
 CREATE SETTINGS PROFILE s3_01294 SETTINGS max_memory_usage = 6000000 TO r1_01294
 CREATE SETTINGS PROFILE s4_01294 TO r1_01294
+-- readonly ambiguity
+CREATE SETTINGS PROFILE s1_01294 SETTINGS readonly = 1
+CREATE SETTINGS PROFILE s2_01294 SETTINGS readonly READONLY
+CREATE SETTINGS PROFILE s3_01294 SETTINGS INHERIT readonly
+CREATE SETTINGS PROFILE s4_01294 SETTINGS INHERIT readonly, INHERIT readonly
+CREATE SETTINGS PROFILE s5_01294 SETTINGS INHERIT readonly, readonly = 1
+CREATE SETTINGS PROFILE s6_01294 SETTINGS INHERIT readonly, readonly READONLY
 -- system.settings_profiles
 s1_01294	local directory	0	0	[]	[]
 s2_01294	local directory	1	0	['r1_01294']	[]
diff --git a/tests/queries/0_stateless/01294_create_settings_profile.sql b/tests/queries/0_stateless/01294_create_settings_profile.sql
index 2d34042f2b44..9dbabd3f0681 100644
--- a/tests/queries/0_stateless/01294_create_settings_profile.sql
+++ b/tests/queries/0_stateless/01294_create_settings_profile.sql
@@ -87,6 +87,21 @@ ALTER PROFILE s2_01294, s3_01294, s4_01294 TO r1_01294;
 SHOW CREATE PROFILE s1_01294, s2_01294, s3_01294, s4_01294;
 DROP PROFILE s1_01294, s2_01294, s3_01294, s4_01294;
 
+SELECT '-- readonly ambiguity';
+CREATE PROFILE s1_01294 SETTINGS readonly=1;
+CREATE PROFILE s2_01294 SETTINGS readonly readonly;
+CREATE PROFILE s3_01294 SETTINGS profile readonly;
+CREATE PROFILE s4_01294 SETTINGS profile readonly, readonly;
+CREATE PROFILE s5_01294 SETTINGS profile readonly, readonly=1;
+CREATE PROFILE s6_01294 SETTINGS profile readonly, readonly readonly;
+SHOW CREATE PROFILE s1_01294;
+SHOW CREATE PROFILE s2_01294;
+SHOW CREATE PROFILE s3_01294;
+SHOW CREATE PROFILE s4_01294;
+SHOW CREATE PROFILE s5_01294;
+SHOW CREATE PROFILE s6_01294;
+DROP PROFILE s1_01294, s2_01294, s3_01294, s4_01294, s5_01294, s6_01294;
+
 SELECT '-- system.settings_profiles';
 CREATE PROFILE s1_01294;
 CREATE PROFILE s2_01294 SETTINGS readonly=0 TO r1_01294;;