libmysql/libmysql.c

    keep vio from being freed twice when we are low on memory
mysys/safemalloc.c
    changes for --safemalloc-mem-limit
sql/mini_client.cc
    keep vio from being freed twice
sql/mysqld.cc
    changes for --safemalloc-mem-limit
sql/slave.cc
    prevent closing connection twice
sql/sql_string.h
    shrink() did not work right when my_realloc() failed

.bzrignore

@@ -163,3 +163,4 @@ include/.my_sys.h.swp
 PENDING/2000-10-25.01
 PENDING/2000-10-25.02
 support-files/mysql-3.23.27-beta.spec
+.gdb_history

libmysql/libmysql.c

@@ -1333,6 +1333,7 @@ mysql_real_connect(MYSQL *mysql,const char *host, const char *user,
   if (!net->vio || my_net_init(net, net->vio))
   {
     vio_delete(net->vio);
+    net->vio = 0;
     net->last_errno=CR_OUT_OF_MEMORY;
     strmov(net->last_error,ER(net->last_errno));
     goto error;

mysys/safemalloc.c

@@ -73,6 +73,10 @@
 #include "my_static.h"
 #include "mysys_err.h"
 
+#ifndef DBUG_OFF
+ulonglong safemalloc_mem_limit = 0;
+#endif
+
 #define pNext		tInt._pNext
 #define pPrev		tInt._pPrev
 #define sFileName	tInt._sFileName
@@ -125,9 +129,16 @@ gptr _mymalloc (uint uSize, const char *sFile, uint uLine, myf MyFlags)
     DBUG_ENTER("_mymalloc");
     DBUG_PRINT("enter",("Size: %u",uSize));
 
+
     if (!sf_malloc_quick)
       (void) _sanity (sFile, uLine);
 
+#ifndef DBUG_OFF    
+    if(safemalloc_mem_limit &&
+       uSize + lCurMemory > safemalloc_mem_limit)
+      pTmp = 0;
+    else
+#endif      
        /* Allocate the physical memory */
        pTmp = (struct remember *) malloc (
 		sizeof (struct irem)			/* remember data  */

sql/mini_client.cc

@@ -611,6 +611,7 @@ mc_mysql_connect(MYSQL *mysql,const char *host, const char *user,
   if (!net->vio || my_net_init(net, net->vio))
   {
     vio_delete(net->vio);
+    net->vio = 0; // safety
     net->last_errno=CR_OUT_OF_MEMORY;
     strmov(net->last_error,ER(net->last_errno));
     goto error;

sql/mysqld.cc

@@ -248,6 +248,10 @@ double log_10[32];			/* 10 potences */
 I_List<THD> threads,thread_cache;
 time_t start_time;
 
+#if !defined(DBUG_OFF) && defined(SAFEMALLOC)
+extern ulonglong safemalloc_mem_limit;
+#endif
+
 pthread_key(MEM_ROOT*,THR_MALLOC);
 pthread_key(THD*, THR_THD);
 pthread_key(NET*, THR_NET);
@@ -2228,7 +2232,7 @@ enum options {
                OPT_BINLOG_IGNORE_DB,     OPT_WANT_CORE,
 	       OPT_SKIP_CONCURRENT_INSERT, OPT_MEMLOCK, OPT_MYISAM_RECOVER,
 	       OPT_REPLICATE_REWRITE_DB, OPT_SERVER_ID, OPT_SKIP_SLAVE_START,
-	       OPT_SKIP_INNOBASE
+	       OPT_SKIP_INNOBASE,OPT_SAFEMALLOC_MEM_LIMIT
 };
 
 static struct option long_options[] = {
@@ -2284,6 +2288,10 @@ static struct option long_options[] = {
   {"master-info-file",      required_argument, 0, (int) OPT_MASTER_INFO_FILE},
   {"myisam-recover",	    optional_argument, 0, (int) OPT_MYISAM_RECOVER},
   {"memlock",		    no_argument,       0, (int) OPT_MEMLOCK},
+#if !defined(DBUG_OFF) && defined(SAFEMALLOC)
+  {"safemalloc-mem-limit",  required_argument, 0, (int)
+     OPT_SAFEMALLOC_MEM_LIMIT},
+#endif    
   {"new",                   no_argument,       0, 'n'},
   {"old-protocol",          no_argument,       0, 'o'},
 #ifdef ONE_THREAD
@@ -2797,6 +2805,11 @@ static void get_options(int argc,char **argv)
     case 'P':
       mysql_port= (unsigned int) atoi(optarg);
       break;
+#if !defined(DBUG_OFF) && defined(SAFEMALLOC)      
+    case OPT_SAFEMALLOC_MEM_LIMIT:
+      safemalloc_mem_limit = atoi(optarg);
+      break;
+#endif      
     case OPT_SOCKET:
       mysql_unix_port= optarg;
       break;

sql/slave.cc

@@ -273,7 +273,10 @@ int fetch_nx_table(THD* thd, MASTER_INFO* mi)
   error = 0;
  err:
   if(mysql)
+    {
      mc_mysql_close(mysql);
+     mysql = 0;
+    }
   if(nx_errno && thd->net.vio)
     send_error(&thd->net, nx_errno, "Error in fetch_nx_table");
   
@@ -942,7 +945,10 @@ pthread_handler_decl(handle_slave,arg __attribute__((unused)))
  err:
   thd->query = thd->db = 0; // extra safety
   if(mysql)
+    {
       mc_mysql_close(mysql);
+      mysql = 0;
+    }
   thd->proc_info = "waiting for slave mutex on exit";
   pthread_mutex_lock(&LOCK_slave);
   slave_running = 0;

sql/sql_string.h

@@ -125,7 +125,7 @@ public:
       char *new_ptr;
       if (!(new_ptr=(char*) my_realloc(Ptr,arg_length,MYF(0))))
       {
-	(void) my_free(Ptr,MYF(0));
+	Alloced_length = 0;
 	real_alloc(arg_length);
       }
       else