MDEV-26611: ERROR_INDEX isn't intuitively clear

Fixup for MDEV-10075

Analysis: ERROR_INDEX implemented in MDEV-10075 was not intuitively clear.

Fix: changed parser to use ROW_NUMBER instead of ERROR_INDEX. Removed
ERROR_INDEX and ERROR_INDEX_SYM from related files. Changed m_error_index
to m_row_number.

mysql-test/suite/perfschema/r/start_server_low_digest_sql_length.result

@@ -8,5 +8,5 @@ SELECT 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1
 ####################################
 SELECT event_name, digest, digest_text, sql_text FROM events_statements_history_long;
 event_name	digest	digest_text	sql_text
-statement/sql/select	dfe1e2b52a48f7294a6385d229770021	SELECT ? + ? + 	SELECT ...
-statement/sql/truncate	6aa520d69a5b4c9035650e7deeae48fd	TRUNCATE TABLE 	truncat...
+statement/sql/select	ca9181d6d668396d467dd974f58a9402	SELECT ? + ? + 	SELECT ...
+statement/sql/truncate	460cb5329baea0e4242059cfda01d1d7	TRUNCATE TABLE 	truncat...

sql/lex.h

@@ -222,7 +222,6 @@ SYMBOL symbols[] = {
   { "ENUM",		SYM(ENUM)},
   { "ERROR",            SYM(ERROR_SYM)},
   { "ERRORS",		SYM(ERRORS)},
-  { "ERROR_INDEX",      SYM(ERROR_INDEX_SYM)},
   { "ESCAPE",		SYM(ESCAPE_SYM)},
   { "ESCAPED",		SYM(ESCAPED)},
   { "EVENT",		SYM(EVENT_SYM)},
@@ -569,6 +568,8 @@ SYMBOL symbols[] = {
   { "ROWTYPE",          SYM(ROWTYPE_MARIADB_SYM)},
   { "ROW_COUNT",        SYM(ROW_COUNT_SYM)},
   { "ROW_FORMAT",	SYM(ROW_FORMAT_SYM)},
+  /** sql_function and condition_property_name for GET DIAGNOSTICS */
+  { "ROW_NUMBER",	SYM(ROW_NUMBER_SYM)},
   { "RTREE",		SYM(RTREE_SYM)},
   { "SAVEPOINT",	SYM(SAVEPOINT_SYM)},
   { "SCHEDULE",		SYM(SCHEDULE_SYM)},
@@ -783,7 +784,6 @@ SYMBOL sql_functions[] = {
   { "PERCENTILE_CONT",  SYM(PERCENTILE_CONT_SYM)},
   { "PERCENTILE_DISC",  SYM(PERCENTILE_DISC_SYM)},
   { "RANK",             SYM(RANK_SYM)},
-  { "ROW_NUMBER",       SYM(ROW_NUMBER_SYM)},
   { "SESSION_USER",     SYM(USER_SYM)},
   { "STD",		SYM(STD_SYM)},
   { "STDDEV",		SYM(STD_SYM)},

sql/sql_error.h

@@ -306,7 +306,8 @@ class Sql_condition_items
   /** SQL CURSOR_NAME condition item. */
   String m_cursor_name;
 
-  ulong m_error_index;
+  /** SQL ROW_NUMBER condition item. */
+  ulong m_row_number;
 
   Sql_condition_items()
    :m_class_origin((const char*) NULL, 0, & my_charset_utf8mb3_bin),
@@ -319,7 +320,7 @@ class Sql_condition_items
     m_table_name((const char*) NULL, 0, & my_charset_utf8mb3_bin),
     m_column_name((const char*) NULL, 0, & my_charset_utf8mb3_bin),
     m_cursor_name((const char*) NULL, 0, & my_charset_utf8mb3_bin),
-    m_error_index(0)
+    m_row_number(0)
   { }
 
   void clear()
@@ -334,7 +335,7 @@ class Sql_condition_items
     m_table_name.length(0);
     m_column_name.length(0);
     m_cursor_name.length(0);
-    m_error_index= 0;
+    m_row_number= 0;
   }
 };
 
@@ -446,7 +447,7 @@ class Sql_condition : public Sql_alloc,
     DBUG_ASSERT(value.get_sql_errno() != 0);
     DBUG_ASSERT(msg != NULL);
     set_builtin_message_text(msg);
-    m_error_index= current_row_for_warning;
+    m_row_number= current_row_for_warning;
   }
 
   /** Destructor. */

sql/sql_get_diagnostics.cc

@@ -338,8 +338,8 @@ Condition_information_item::get_value(THD *thd, const Sql_condition *cond)
     str.set_ascii(cond->get_sqlstate(), strlen(cond->get_sqlstate()));
     value= make_utf8_string_item(thd, &str);
     break;
-  case ERROR_INDEX:
-    value= new (thd->mem_root) Item_uint(thd, cond->m_error_index);
+  case ROW_NUMBER:
+    value= new (thd->mem_root) Item_uint(thd, cond->m_row_number);
   }
 
   DBUG_RETURN(value);

sql/sql_get_diagnostics.h

@@ -255,7 +255,7 @@ class Condition_information_item : public Diagnostics_information_item
     MESSAGE_TEXT,
     MYSQL_ERRNO,
     RETURNED_SQLSTATE,
-    ERROR_INDEX
+    ROW_NUMBER
   };
 
   /**

sql/sql_yacc.yy

@@ -974,7 +974,6 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %token  <kwd>  MUTEX_SYM
 %token  <kwd>  MYSQL_SYM
 %token  <kwd>  MYSQL_ERRNO_SYM
-%token  <kwd>  ERROR_INDEX_SYM
 %token  <kwd>  NAMES_SYM                     /* SQL-2003-N */
 %token  <kwd>  NAME_SYM                      /* SQL-2003-N */
 %token  <kwd>  NATIONAL_SYM                  /* SQL-2003-R */
@@ -3631,8 +3630,8 @@ condition_information_item_name:
           { $$= Condition_information_item::MYSQL_ERRNO; }
         | RETURNED_SQLSTATE_SYM
           { $$= Condition_information_item::RETURNED_SQLSTATE; }
-        | ERROR_INDEX_SYM
-          { $$= Condition_information_item::ERROR_INDEX; }
+        | ROW_NUMBER_SYM
+          { $$= Condition_information_item::ROW_NUMBER; }
         ;
 
 sp_decl_ident:
@@ -15664,7 +15663,6 @@ keyword_sp_var_and_label:
         | INVOKER_SYM
         | IMPORT
         | INDEXES
-        | ERROR_INDEX_SYM
         | INITIAL_SIZE_SYM
         | IO_SYM
         | IPC_SYM

tests/mysql_client_test.c

@@ -21580,7 +21580,7 @@ void test_mdev_10075()
 
   mysql_stmt_close(stmt);
 
-  rc= mysql_query(mysql, "GET DIAGNOSTICS CONDITION 1 @var1 = ERROR_INDEX");
+  rc= mysql_query(mysql, "GET DIAGNOSTICS CONDITION 1 @var1 = ROW_NUMBER");
   myquery(rc);
 
   rc= mysql_query(mysql, "SELECT @var1");