From 2d00efaab74b14bad7dcfda43dbf74ccf4e714c8 Mon Sep 17 00:00:00 2001
From: hopebo <hopelee1994@gmail.com>
Date: Wed, 21 Oct 2020 15:35:42 +0800
Subject: [PATCH] Bugfix Regexp_engine::Replace doesn't reset error code after
 processing a record

Description
-----------
When REGEXP_REPLACE is used in a SQL, the function Regexp_engine::Replace() is
responsible for dealing with records one by one.

But after processing on a record, the function doesn't reset the value of error
code(Regexp_engine::m_error_code). And the error code will affect the execution
of processing on the next record, which may cause a problem.

Reset error code to U_ZERO_ERROR after checking the icu status. Function
check_icu_status() will be called every time after a whole regexp operation
has happened.
---
 sql/regexp/errors.cc        | 11 +++++++----
 sql/regexp/errors.h         |  2 +-
 sql/regexp/regexp_engine.cc |  4 ++--
 sql/regexp/regexp_engine.h  |  6 +++---
 4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/sql/regexp/errors.cc b/sql/regexp/errors.cc
index 6d4ea332b18..244238b429a 100644
--- a/sql/regexp/errors.cc
+++ b/sql/regexp/errors.cc
@@ -74,10 +74,13 @@ std::unordered_map<UErrorCode, int, UErrorCodeHash> error_map = {
     {U_REGEX_INVALID_CAPTURE_GROUP_NAME, ER_REGEXP_INVALID_CAPTURE_GROUP_NAME},
     {U_REGEX_INVALID_FLAG, ER_REGEXP_INVALID_FLAG}};
 
-bool check_icu_status(UErrorCode status, const UParseError *parse_error) {
-  if (status == U_ZERO_ERROR || U_SUCCESS(status)) return false;
+bool check_icu_status(UErrorCode *status, const UParseError *parse_error) {
+  if (U_SUCCESS(*status)) {
+    *status = U_ZERO_ERROR;
+    return false;
+  }
 
-  int error_code = error_map[status];
+  int error_code = error_map[*status];
   if (error_code == 0) {
     /*
       If this fires, there is no translation from this ICU status code to a
@@ -86,7 +89,7 @@ bool check_icu_status(UErrorCode status, const UParseError *parse_error) {
       regexp".
     */
     DBUG_ASSERT(false);
-    my_error(ER_REGEXP_ERROR, MYF(0), u_errorName(status));
+    my_error(ER_REGEXP_ERROR, MYF(0), u_errorName(*status));
     return true;
   }
 
diff --git a/sql/regexp/errors.h b/sql/regexp/errors.h
index 0217bdab4eb..b4841e10b4f 100644
--- a/sql/regexp/errors.h
+++ b/sql/regexp/errors.h
@@ -28,7 +28,7 @@
 
 namespace regexp {
 
-bool check_icu_status(UErrorCode status,
+bool check_icu_status(UErrorCode *status,
                       const UParseError *parse_error = nullptr);
 
 }  // namespace regexp
diff --git a/sql/regexp/regexp_engine.cc b/sql/regexp/regexp_engine.cc
index 2e03e572b6a..1a8feea0556 100644
--- a/sql/regexp/regexp_engine.cc
+++ b/sql/regexp/regexp_engine.cc
@@ -59,7 +59,7 @@ bool Regexp_engine::Matches(int start, int occurrence) {
   for (int i = 1; i < occurrence && found; ++i)
     found = uregex_findNext(m_re, &m_error_code);
 
-  check_icu_status(m_error_code);
+  check_icu_status(&m_error_code);
   return found;
 }
 
@@ -100,7 +100,7 @@ const std::u16string &Regexp_engine::Replace(const std::u16string &replacement,
   // ... put the part after the matches back.
   AppendTail();
 
-  check_icu_status(m_error_code);
+  check_icu_status(&m_error_code);
   m_replace_buffer.resize(m_replace_buffer_pos);
   return m_replace_buffer;
 }
diff --git a/sql/regexp/regexp_engine.h b/sql/regexp/regexp_engine.h
index c4d7325ab15..a62f9976a44 100644
--- a/sql/regexp/regexp_engine.h
+++ b/sql/regexp/regexp_engine.h
@@ -106,12 +106,12 @@ class Regexp_engine {
     uregex_setStackLimit(m_re, stack_limit, &m_error_code);
     uregex_setTimeLimit(m_re, time_limit, &m_error_code);
     uregex_setMatchCallback(m_re, QueryNotKilled, current_thd, &m_error_code);
-    check_icu_status(m_error_code, &error);
+    check_icu_status(&m_error_code, &error);
   }
 
   uint flags() {
     uint flags = uregex_flags(m_re, &m_error_code);
-    check_icu_status(m_error_code);
+    check_icu_status(&m_error_code);
     return flags;
   }
 
@@ -181,7 +181,7 @@ class Regexp_engine {
   String *MatchedSubstring(String *result);
 
   bool IsError() const { return U_FAILURE(m_error_code); }
-  bool CheckError() const { return check_icu_status(m_error_code); }
+  bool CheckError() { return check_icu_status(&m_error_code); }
 
   virtual ~Regexp_engine() { uregex_close(m_re); }
 
-- 
2.19.1.6.gb485710b