BUG#11766444 : MTR PRINTS WRONG FILE AND LINE NUMBER WHEN TESTS FAIL

Description :
=============
When a test case fails, MTR sometimes prints the wrong line number.
This happens if a test case fails inside a while loop and it is not
the first iteration of the loop.

E.g:
----
--let $i = 2
while ($i)
{
  dec $i;
  if (!$i)
  {
    execute this invalid query;
  }
}

When executing the above test case, MTR fails with the following
message:

mysqltest: At line 9: query 'execute this invalid query' failed: 1064:
You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'invalid query' at line 1

Note that the error was on line 7 but the test reports line 9.

Issue :
=======
The variable 'start_lineno' keeping track of the current line number
in a test is not updated after the first iteration and hence printing
the line number of the last line of the loop.

Fix :
=====
Introduced a new variable 'lineno' in 'st_command' structure to keep
track of the the line number for each command. During the iteration
after the first one, use this variable to update the 'start_lineno'
variable to the current line number.

Reviewed-by: Deepa Dixit <[email protected]>
Reviewed-by: Srikanth B R <[email protected]>
RB: 16015

Author: Pavan Naik

client/mysqltest.cc

@@ -572,6 +572,8 @@ struct st_command
   struct st_expected_errors expected_errors;
   char output_file[FN_REFLEN];
   enum enum_commands type;
+  // Line number of the command
+  uint lineno;
 };
 
 TYPELIB command_typelib= {array_elements(command_names),"",
@@ -7368,37 +7370,38 @@ static bool is_delimiter(const char* p)
 }
 
 
-/*
-  Create a command from a set of lines
-
-  SYNOPSIS
-    read_command()
-    command_ptr pointer where to return the new query
-
-  DESCRIPTION
-    Converts lines returned by read_line into a command, this involves
-    parsing the first word in the read line to find the command type.
-
-  A -- comment may contain a valid query as the first word after the
-  comment start. Thus it's always checked to see if that is the case.
-  The advantage with this approach is to be able to execute commands
-  terminated by new line '\n' regardless how many "delimiter" it contain.
-*/
-
-#define MAX_QUERY (256*1024*2) /* 256K -- a test in sp-big is >128K */
+// 256K -- a test in sp-big is >128K
+#define MAX_QUERY (256*1024*2)
 static char read_command_buf[MAX_QUERY];
 
+/// Create a command from a set of lines.
+///
+/// Converts lines returned by read_line into a command, this involves
+/// parsing the first word in the read line to find the command type.
+///
+/// A '`--`' comment may contain a valid query as the first word after
+/// the comment start. Thus it's always checked to see if that is the
+/// case. The advantage with this approach is to be able to execute
+/// commands terminated by new line '\n' regardless how many "delimiter"
+/// it contain.
+///
+/// @param [in] command_ptr pointer where to return the new query
+///
+/// @retval 0 on success, else 1
 static int read_command(struct st_command** command_ptr)
 {
   char *p= read_command_buf;
-  struct st_command* command;
   DBUG_ENTER("read_command");
 
   if (parser.current_line < parser.read_lines)
   {
     *command_ptr= q_lines->at(parser.current_line);
+    // Assign the current command line number
+    start_lineno= (*command_ptr)->lineno;
     DBUG_RETURN(0);
   }
+
+  struct st_command* command;
   if (!(*command_ptr= command=
         (struct st_command*) my_malloc(PSI_NOT_INSTRUMENTED,
                                        sizeof(*command),
@@ -7414,6 +7417,9 @@ static int read_command(struct st_command** command_ptr)
     DBUG_RETURN(1);
   }
 
+  // Set the line number for the command
+  command->lineno= start_lineno;
+
   if (opt_result_format_version == 1)
     convert_to_format_v1(read_command_buf);
 
@@ -7425,24 +7431,24 @@ static int read_command(struct st_command** command_ptr)
   else if (p[0] == '-' && p[1] == '-')
   {
     command->type= Q_COMMENT_WITH_COMMAND;
-    p+= 2; /* Skip past -- */
+    // Skip past '--'
+    p+= 2;
   }
   else if (*p == '\n')
   {
     command->type= Q_EMPTY_LINE;
   }
 
-  /* Skip leading spaces */
+  // Skip leading spaces
   while (*p && my_isspace(charset_info, *p))
     p++;
 
   if (!(command->query_buf= command->query= my_strdup(PSI_NOT_INSTRUMENTED,
                                                       p, MYF(MY_WME))))
     die("Out of memory");
 
-  /*
-    Calculate first word length(the command), terminated
-    by 'space' , '(' or 'delimiter' */
+  // Calculate first word length(the command), terminated
+  // by 'space' , '(' or 'delimiter'
   p= command->query;
   while (*p && !my_isspace(charset_info, *p) && *p != '(' && !is_delimiter(p))
     p++;
@@ -7451,7 +7457,7 @@ static int read_command(struct st_command** command_ptr)
                       static_cast<int>(command->first_word_len),
                       command->query));
 
-  /* Skip spaces between command and first argument */
+  // Skip spaces between command and first argument
   while (*p && my_isspace(charset_info, *p))
     p++;
   command->first_argument= p;

mysql-test/r/mysqltest.result

@@ -1526,3 +1526,7 @@ Hello
 # Outer while condition evalutes to false
 # "Hello" shouldn't be repeated
 Hello
+#
+# BUG#11766444 : MTR PRINTS WRONG FILE AND LINE NUMBER WHEN TESTS FAIL
+#
+mysqltest: At line 7: query 'execute this invalid query' failed: 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'invalid query' at line 1

mysql-test/t/mysqltest.test

@@ -3874,3 +3874,26 @@ while (0)
 
 # Cleanup
 --remove_file $MYSQL_TMP_DIR/bug25840940.inc
+
+--echo #
+--echo # BUG#11766444 : MTR PRINTS WRONG FILE AND LINE NUMBER WHEN TESTS FAIL
+--echo #
+
+--write_file $MYSQLTEST_VARDIR/tmp/bug11766444.test
+--let $counter= 2
+while ($counter)
+{
+  --dec $counter
+  if (!$counter)
+  {
+    execute this invalid query;
+  }
+}
+EOF
+
+# Invalid query at line 7
+--error 1
+--exec $MYSQL_TEST -x $MYSQLTEST_VARDIR/tmp/bug11766444.test 2>&1
+
+# Cleanup
+--remove_file $MYSQLTEST_VARDIR/tmp/bug11766444.test