Contributed patch from Jorge Bernal Ordovás. CLA#42

Bug#27894: mysqlbinlog formats timestamp wrong in comment

Date stamps lack zero padding, and so are meaningless.

Implement minimum-width zero padding for the percent-escape sequences
used in the logging code.

mysql-test/r/mysqlbinlog2.result

@@ -18,7 +18,11 @@ insert into t1 values(null, "f");
 /*!40019 SET @@session.max_insert_delayed_threads=0*/;
 /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
 DELIMITER /*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Start: binlog v 4, server v 5.1.18-beta-debug-log created {yymmdd} {HH:MM:SS} at startup
 ROLLBACK/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 use test/*!*/;
 SET TIMESTAMP=1579609942/*!*/;
 SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=1, @@session.unique_checks=1/*!*/;
@@ -26,21 +30,43 @@ SET @@session.sql_mode=0/*!*/;
 /*!\C latin1 *//*!*/;
 SET @@session.character_set_client=8,@@session.collation_connection=8,@@session.collation_server=8/*!*/;
 create table t1 (a int auto_increment not null primary key, b char(3))/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Intvar
 SET INSERT_ID=1/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 SET TIMESTAMP=1579609942/*!*/;
 insert into t1 values(null, "a")/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Intvar
 SET INSERT_ID=2/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 SET TIMESTAMP=1579609942/*!*/;
 insert into t1 values(null, "b")/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Intvar
 SET INSERT_ID=3/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 SET TIMESTAMP=1579609944/*!*/;
 insert into t1 values(null, "c")/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Intvar
 SET INSERT_ID=4/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 SET TIMESTAMP=1579609946/*!*/;
 insert into t1 values(null, "d")/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Intvar
 SET INSERT_ID=5/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Query	thread_id={integer}	exec_time={integer}	error_code=0
 SET TIMESTAMP=1579609946/*!*/;
 insert into t1 values(null, "e")/*!*/;
+# at {pos}
+#{yymmdd} {HH:MM:SS} server id 1  end_log_pos {pos} 	Rotate to master-bin.000002  pos: {pos}
 DELIMITER ;
 # End of log file
 ROLLBACK /* added by mysqlbinlog */;

mysql-test/t/mysqlbinlog2.test

@@ -43,7 +43,8 @@ select "--- Local --" as "";
 # be time dependent (the Start events). Better than nothing.
 #
 
---exec $MYSQL_BINLOG --short-form $MYSQLTEST_VARDIR/log/master-bin.000001 
+--replace_regex /[[:<:]][0-9]{6} [0-9 ][0-9]:[0-9]{2}:[0-9]{2}[[:>:]]/{yymmdd} {HH:MM:SS}/  /=[0-9]+	/={integer}	/  /# at [0-9]+/# at {pos}/  /(pos:?) [0-9]+/\1 {pos}/
+--exec $MYSQL_BINLOG $MYSQLTEST_VARDIR/log/master-bin.000001 
 
 --disable_query_log
 select "--- offset --" as "";

mysys/mf_iocache2.c

@@ -299,6 +299,7 @@ uint my_b_vprintf(IO_CACHE *info, const char* fmt, va_list args)
   uint minimum_width; /* as yet unimplemented */
   uint minimum_width_sign;
   uint precision; /* as yet unimplemented for anything but %b */
+  my_bool is_zero_padded;
 
   /*
     Store the location of the beginning of a format directive, for the
@@ -334,11 +335,27 @@ uint my_b_vprintf(IO_CACHE *info, const char* fmt, va_list args)
     backtrack= fmt;
     fmt++;
 
+    is_zero_padded= FALSE;
+    minimum_width_sign= 1;
     minimum_width= 0;
     precision= 0;
-    minimum_width_sign= 1;
     /* Skip if max size is used (to be compatible with printf) */
-    while (*fmt == '-') { fmt++; minimum_width_sign= -1; }
+
+process_flags:
+    switch (*fmt)
+    {
+      case '-': 
+        minimum_width_sign= -1; fmt++; goto process_flags;
+      case '0':
+        is_zero_padded= TRUE; fmt++; goto process_flags;
+      case '#':
+        /** @todo Implement "#" conversion flag. */  fmt++; goto process_flags;
+      case ' ':
+        /** @todo Implement " " conversion flag. */  fmt++; goto process_flags;
+      case '+':
+        /** @todo Implement "+" conversion flag. */  fmt++; goto process_flags;
+    }
+
     if (*fmt == '*') {
       precision= (int) va_arg(args, int);
       fmt++;
@@ -367,7 +384,7 @@ uint my_b_vprintf(IO_CACHE *info, const char* fmt, va_list args)
     {
       reg2 char *par = va_arg(args, char *);
       uint length2 = (uint) strlen(par);
-      /* TODO: implement minimum width and precision */
+      /* TODO: implement precision */
       out_length+= length2;
       if (my_b_write(info, par, length2))
 	goto err;
@@ -390,6 +407,21 @@ uint my_b_vprintf(IO_CACHE *info, const char* fmt, va_list args)
 	length2= (uint) (int10_to_str((long) iarg,buff, -10) - buff);
       else
 	length2= (uint) (int10_to_str((long) (uint) iarg,buff,10)- buff);
+
+      /* minimum width padding */
+      if (minimum_width > length2) 
+      {
+        char *buffz;
+                    
+        buffz= my_alloca(minimum_width - length2);
+        if (is_zero_padded)
+          memset(buffz, '0', minimum_width - length2);
+        else
+          memset(buffz, ' ', minimum_width - length2);
+        my_b_write(info, buffz, minimum_width - length2);
+        my_afree(buffz);
+      }
+
       out_length+= length2;
       if (my_b_write(info, buff, length2))
 	goto err;