Fix memory clobber problem reported by John Hansen: plperl_safe_init()

may expand the Perl stack, therefore we must SPAGAIN to reload the local
stack pointer after calling it.  Also a couple other marginal readability
improvements.

diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 45a4f7aff764645fafd03feaf68dbc740a9ef951..fc0a94991884102b73d920cdce7d080a0648c34c 100644 (file)
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -33,7 +33,7 @@
  *       ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.57 2004/11/17 21:23:36 tgl Exp $
+ *       $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.58 2004/11/18 21:35:42 tgl Exp $
  *
  **********************************************************************/
 
@@ -240,7 +240,6 @@ plperl_init_interp(void)
         * Initialize the proc and query hash tables
         ************************************************************/
        plperl_proc_hash = newHV();
-
 }
 
 
@@ -497,10 +496,7 @@ plperl_get_elem(HV *hash, char *key)
 {
        SV **svp = hv_fetch(hash, key, strlen(key), FALSE);
        if (!svp)
-       {
                elog(ERROR, "plperl: key '%s' not found", key);
-               return NULL;
-       }
        return SvTYPE(*svp) == SVt_NULL ? NULL : SvPV(*svp, PL_na);
 }
 
@@ -659,7 +655,10 @@ plperl_create_sub(char *s, bool trusted)
        int                     count;
 
        if (trusted && !plperl_safe_init_done)
+       {
                plperl_safe_init();
+               SPAGAIN;
+       }
 
        ENTER;
        SAVETMPS;
@@ -760,50 +759,40 @@ plperl_call_perl_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo)
        XPUSHs(sv_2mortal(newSVpv("undef", 0)));
        for (i = 0; i < desc->nargs; i++)
        {
-               if (desc->arg_is_rowtype[i])
+               if (fcinfo->argnull[i])
+                       XPUSHs(&PL_sv_undef);
+               else if (desc->arg_is_rowtype[i])
                {
-                       if (fcinfo->argnull[i])
-                               XPUSHs(&PL_sv_undef);
-                       else
-                       {
-                               HeapTupleHeader td;
-                               Oid                     tupType;
-                               int32           tupTypmod;
-                               TupleDesc       tupdesc;
-                               HeapTupleData tmptup;
-                               SV                 *hashref;
-
-                               td = DatumGetHeapTupleHeader(fcinfo->arg[i]);
-                               /* Extract rowtype info and find a tupdesc */
-                               tupType = HeapTupleHeaderGetTypeId(td);
-                               tupTypmod = HeapTupleHeaderGetTypMod(td);
-                               tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
-                               /* Build a temporary HeapTuple control structure */
-                               tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
-                               tmptup.t_data = td;
-
-                               /*
-                                * plperl_build_tuple_argument better return a mortal SV.
-                                */
-                               hashref = plperl_build_tuple_argument(&tmptup, tupdesc);
-                               XPUSHs(hashref);
-                       }
+                       HeapTupleHeader td;
+                       Oid                     tupType;
+                       int32           tupTypmod;
+                       TupleDesc       tupdesc;
+                       HeapTupleData tmptup;
+                       SV                 *hashref;
+
+                       td = DatumGetHeapTupleHeader(fcinfo->arg[i]);
+                       /* Extract rowtype info and find a tupdesc */
+                       tupType = HeapTupleHeaderGetTypeId(td);
+                       tupTypmod = HeapTupleHeaderGetTypMod(td);
+                       tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
+                       /* Build a temporary HeapTuple control structure */
+                       tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
+                       tmptup.t_data = td;
+
+                       /* plperl_build_tuple_argument better return a mortal SV */
+                       hashref = plperl_build_tuple_argument(&tmptup, tupdesc);
+                       XPUSHs(hashref);
                }
                else
                {
-                       if (fcinfo->argnull[i])
-                               XPUSHs(&PL_sv_undef);
-                       else
-                       {
-                               char       *tmp;
-
-                               tmp = DatumGetCString(FunctionCall3(&(desc->arg_out_func[i]),
-                                                                                                       fcinfo->arg[i],
-                                                          ObjectIdGetDatum(desc->arg_typioparam[i]),
-                                                                                                       Int32GetDatum(-1)));
-                               XPUSHs(sv_2mortal(newSVpv(tmp, 0)));
-                               pfree(tmp);
-                       }
+                       char       *tmp;
+
+                       tmp = DatumGetCString(FunctionCall3(&(desc->arg_out_func[i]),
+                                                                                               fcinfo->arg[i],
+                                                                       ObjectIdGetDatum(desc->arg_typioparam[i]),
+                                                                                               Int32GetDatum(-1)));
+                       XPUSHs(sv_2mortal(newSVpv(tmp, 0)));
+                       pfree(tmp);
                }
        }
        PUTBACK;
@@ -848,6 +837,7 @@ plperl_call_perl_trigger_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo, S
 {
        dSP;
        SV                 *retval;
+       Trigger    *tg_trigger;
        int                     i;
        int                     count;
 
@@ -856,8 +846,9 @@ plperl_call_perl_trigger_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo, S
 
        PUSHMARK(sp);
        XPUSHs(td);
-       for (i = 0; i < ((TriggerData *) fcinfo->context)->tg_trigger->tgnargs; i++)
-               XPUSHs(sv_2mortal(newSVpv(((TriggerData *) fcinfo->context)->tg_trigger->tgargs[i], 0)));
+       tg_trigger = ((TriggerData *) fcinfo->context)->tg_trigger;
+       for (i = 0; i < tg_trigger->tgnargs; i++)
+               XPUSHs(sv_2mortal(newSVpv(tg_trigger->tgargs[i], 0)));
        PUTBACK;
 
        count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL | G_KEEPERR);