Repair access-to-already-freed-memory error recently introduced into

VACUUM.

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index dc8ebf4635e74abc64a163be343a856cc8e7d023..3cd9b026519fe2f0b8b0baa9604cd70fe42cd08f 100644 (file)
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.141 2000/02/24 04:34:38 inoue Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.142 2000/03/08 23:41:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -144,6 +144,7 @@ PortalVariableMemory CommonSpecialPortalGetMemory(void)
 {
        return PortalGetVariableMemory(vc_portal);
 }
+
 bool CommonSpecialPortalIsOpen(void)
 {
        return CommonSpecialPortalInUse;
@@ -153,6 +154,7 @@ void
 vacuum(char *vacrel, bool verbose, bool analyze, List *va_spec)
 {
        NameData        VacRel;
+       Name            VacRelName;
        PortalVariableMemory pmem;
        MemoryContext old;
        List       *le;
@@ -173,17 +175,22 @@ vacuum(char *vacrel, bool verbose, bool analyze, List *va_spec)
        if (IsTransactionBlock())
                elog(ERROR, "VACUUM cannot run inside a BEGIN/END block");
 
-       /* initialize vacuum cleaner, particularly vc_portal */
-       vc_init();
-
        if (verbose)
                MESSAGE_LEVEL = NOTICE;
        else
                MESSAGE_LEVEL = DEBUG;
 
-       /* vacrel gets de-allocated on transaction commit, so copy it */
+       /* Create special portal for cross-transaction storage */
+       CommonSpecialPortalOpen();
+
+       /* vacrel gets de-allocated on xact commit, so copy it to safe storage */
        if (vacrel)
-               strcpy(NameStr(VacRel), vacrel);
+       {
+               namestrcpy(&VacRel, vacrel);
+               VacRelName = &VacRel;
+       }
+       else
+               VacRelName = NULL;
 
        /* must also copy the column list, if any, to safe storage */
        pmem = CommonSpecialPortalGetMemory();
@@ -196,11 +203,18 @@ vacuum(char *vacrel, bool verbose, bool analyze, List *va_spec)
        }
        MemoryContextSwitchTo(old);
 
+       /*
+        * Start up the vacuum cleaner.
+        *
+        * NOTE: since this commits the current transaction, the memory holding
+        * any passed-in parameters gets freed here.  We must have already copied
+        * pass-by-reference parameters to safe storage.  Don't make me fix this
+        * again!
+        */
+       vc_init();
+
        /* vacuum the database */
-       if (vacrel)
-               vc_vacuum(&VacRel, analyze, va_cols);
-       else
-               vc_vacuum(NULL, analyze, NIL);
+       vc_vacuum(VacRelName, analyze, va_cols);
 
        /* clean up */
        vc_shutdown();
@@ -229,8 +243,6 @@ vacuum(char *vacrel, bool verbose, bool analyze, List *va_spec)
 static void
 vc_init()
 {
-       CommonSpecialPortalOpen();
-
        /* matches the StartTransaction in PostgresMain() */
        CommitTransactionCommand();
 }
@@ -252,6 +264,7 @@ vc_shutdown()
         */
        unlink(RELCACHE_INIT_FILENAME);
 
+       /* Clean up working storage */
        CommonSpecialPortalClose();
 
        /* matches the CommitTransaction in PostgresMain() */