From 70eaae38f2fe5c91d6a43b5166df623996826042 Mon Sep 17 00:00:00 2001
From: Ewout <e@ewout.name>
Date: Sat, 30 May 2020 21:44:22 +0200
Subject: [PATCH] Fix visitParamExtractRaw for strings with unbalanced { or [.

Closes #11254 .
---
 src/Functions/visitParamExtractRaw.cpp              | 13 ++++++++-----
 .../00539_functions_for_working_with_json.reference |  2 ++
 .../00539_functions_for_working_with_json.sql       |  2 ++
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/Functions/visitParamExtractRaw.cpp b/src/Functions/visitParamExtractRaw.cpp
index 7a02d29e446..ef41e9bc900 100644
--- a/src/Functions/visitParamExtractRaw.cpp
+++ b/src/Functions/visitParamExtractRaw.cpp
@@ -22,6 +22,14 @@ struct ExtractRaw
                 expects_end.pop_back();
                 current_expect_end = expects_end.empty() ? 0 : expects_end.back();
             }
+            else if (current_expect_end == '"')
+            {
+                /// skip backslash
+                if (*pos == '\\' && pos + 1 < end && pos[1] == '"')
+                {
+                    pos++;
+                }
+            }
             else
             {
                 switch (*pos)
@@ -38,11 +46,6 @@ struct ExtractRaw
                         current_expect_end = '"';
                         expects_end.push_back(current_expect_end);
                         break;
-                    case '\\':
-                        /// skip backslash
-                        if (pos + 1 < end && pos[1] == '"')
-                            pos++;
-                        break;
                     default:
                         if (!current_expect_end && (*pos == ',' || *pos == '}'))
                         {
diff --git a/tests/queries/0_stateless/00539_functions_for_working_with_json.reference b/tests/queries/0_stateless/00539_functions_for_working_with_json.reference
index ee7fb68b7c2..c0399f8ab2e 100644
--- a/tests/queries/0_stateless/00539_functions_for_working_with_json.reference
+++ b/tests/queries/0_stateless/00539_functions_for_working_with_json.reference
@@ -9,5 +9,7 @@ test"string
  "test_string"
  "test\\"string"
  "test\\"string"
+ "{"
+ "["
  ["]", "2", "3"]
  {"nested" : [1,2,3]}
diff --git a/tests/queries/0_stateless/00539_functions_for_working_with_json.sql b/tests/queries/0_stateless/00539_functions_for_working_with_json.sql
index 8a4d1794293..514b5f2e5ea 100644
--- a/tests/queries/0_stateless/00539_functions_for_working_with_json.sql
+++ b/tests/queries/0_stateless/00539_functions_for_working_with_json.sql
@@ -11,5 +11,7 @@ SELECT visitParamExtractRaw('{"myparam":"test_string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test_string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test\\"string"}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": "test\\"string", "other":123}', 'myparam');
+SELECT visitParamExtractRaw('{"myparam": "{"}', 'myparam');
+SELECT visitParamExtractRaw('{"myparam": "["}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": ["]", "2", "3"], "other":123}', 'myparam');
 SELECT visitParamExtractRaw('{"myparam": {"nested" : [1,2,3]}, "other":123}', 'myparam');