Merge mysql.com:/misc/mysql/31752_/41-31752_

into  mysql.com:/misc/mysql/31752_/50-31752_

sql/log.cc

@@ -1290,7 +1290,7 @@ void MYSQL_LOG::make_log_name(char* buf, const char* log_ident)
   if (dir_len > FN_REFLEN)
     dir_len=FN_REFLEN-1;
   strnmov(buf, log_file_name, dir_len);
-  strmake(buf+dir_len, log_ident, FN_REFLEN - dir_len);
+  strmake(buf+dir_len, log_ident, FN_REFLEN - dir_len -1);
 }
 
 

sql/repl_failsafe.cc

@@ -922,7 +922,7 @@ bool load_master_data(THD* thd)
 			     0, (SLAVE_IO | SLAVE_SQL)))
           my_message(ER_MASTER_INFO, ER(ER_MASTER_INFO), MYF(0));
 	strmake(active_mi->master_log_name, row[0],
-		sizeof(active_mi->master_log_name));
+		sizeof(active_mi->master_log_name) -1);
 	active_mi->master_log_pos= my_strtoll10(row[1], (char**) 0, &error_2);
         /* at least in recent versions, the condition below should be false */
 	if (active_mi->master_log_pos < BIN_LOG_HEADER_SIZE)

sql/set_var.cc

@@ -1752,7 +1752,7 @@ bool sys_var::check_set(THD *thd, set_var *var, TYPELIB *enum_names)
 					    &not_used));
     if (error_len)
     {
-      strmake(buff, error, min(sizeof(buff), error_len));
+      strmake(buff, error, min(sizeof(buff) - 1, error_len));
       goto err;
     }
   }

sql/unireg.cc

@@ -165,6 +165,9 @@ bool mysql_create_frm(THD *thd, my_string file_name,
   strmake((char*) forminfo+47, create_info->comment.str ?
           create_info->comment.str : "", create_info->comment.length);
   forminfo[46]=(uchar) create_info->comment.length;
+#ifdef EXTRA_DEBUG
+  memset((char*) forminfo+47 + forminfo[46], 0, 61 - forminfo[46]);
+#endif
   if (my_pwrite(file,(byte*) fileinfo,64,0L,MYF_RW) ||
       my_pwrite(file,(byte*) keybuff,key_info_length,
 		(ulong) uint2korr(fileinfo+6),MYF_RW))

strings/strmake.c

@@ -27,23 +27,25 @@
 #include <my_global.h>
 #include "m_string.h"
 
-#ifdef BAD_STRING_COMPILER
-
-char *strmake(char *dst,const char *src,uint length)
+char *strmake(register char *dst, register const char *src, uint length)
 {
-  reg1 char *res;
-
-  if ((res=memccpy(dst,src,0,length)))
-    return res-1;
-  dst[length]=0;
-  return dst+length;
-}
-
-#define strmake strmake_overlapp	/* Use orginal for overlapping str */
+#ifdef EXTRA_DEBUG
+  /*
+    'length' is the maximum length of the string; the buffer needs
+    to be one character larger to accomodate the terminating '\0'.
+    This is easy to get wrong, so we make sure we write to the
+    entire length of the buffer to identify incorrect buffer-sizes.
+    We only initialise the "unused" part of the buffer here, a) for
+    efficiency, and b) because dst==src is allowed, so initialising
+    the entire buffer would overwrite the source-string. Also, we
+    write a character rather than '\0' as this makes spotting these
+    problems in the results easier.
+  */
+  uint n= strlen(src) + 1;
+  if (n <= length)
+    memset(dst + n, (int) 'Z', length - n + 1);
 #endif
 
-char *strmake(register char *dst, register const char *src, uint length)
-{
   while (length--)
     if (! (*dst++ = *src++))
       return dst-1;