Check values passed back from PLPerl to the database, via function return,

trigger tuple modification or SPI call, to ensure they are valid in the
server encoding. Along the way, replace uses of SvPV(foo, PL_na)
with SvPV_nolen(foo) as recommended in the perl docs. Bug report from
Hannu Krosing.

src/pl/plperl/plperl.c

@@ -1,7 +1,7 @@
 /**********************************************************************
  * plperl.c - perl as a procedural language for PostgreSQL
  *
- *	  $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.157 2009/12/31 19:41:37 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.158 2010/01/04 20:29:59 adunstan Exp $
  *
  **********************************************************************/
 
@@ -630,7 +630,13 @@ plperl_build_tuple_result(HV *perlhash, AttInMetadata *attinmeta)
 					 errmsg("Perl hash contains nonexistent column \"%s\"",
 							key)));
 		if (SvOK(val))
-			values[attn - 1] = SvPV(val, PL_na);
+		{
+			char * aval;
+
+			aval = SvPV_nolen(val);
+			pg_verifymbstr(aval, strlen(aval), false);
+			values[attn - 1] = aval;
+		}
 	}
 	hv_iterinit(perlhash);
 
@@ -829,8 +835,12 @@ plperl_modify_tuple(HV *hvTD, TriggerData *tdata, HeapTuple otup)
 		atttypmod = tupdesc->attrs[attn - 1]->atttypmod;
 		if (SvOK(val))
 		{
+			char * aval;
+
+			aval = SvPV_nolen(val);
+			pg_verifymbstr(aval,strlen(aval), false);
 			modvalues[slotsused] = InputFunctionCall(&finfo,
-													 SvPV(val, PL_na),
+													 aval,
 													 typioparam,
 													 atttypmod);
 			modnulls[slotsused] = ' ';
@@ -1125,7 +1135,7 @@ plperl_create_sub(const char *proname, const char *s, bool trusted)
 		LEAVE;
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
-				 errmsg("%s", strip_trailing_ws(SvPV(ERRSV, PL_na)))));
+				 errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV)))));
 	}
 
 	/*
@@ -1253,7 +1263,7 @@ plperl_call_perl_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo)
 		LEAVE;
 		/* XXX need to find a way to assign an errcode here */
 		ereport(ERROR,
-				(errmsg("%s", strip_trailing_ws(SvPV(ERRSV, PL_na)))));
+				(errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV)))));
 	}
 
 	retval = newSVsv(POPs);
@@ -1309,7 +1319,7 @@ plperl_call_perl_trigger_func(plperl_proc_desc *desc, FunctionCallInfo fcinfo,
 		LEAVE;
 		/* XXX need to find a way to assign an errcode here */
 		ereport(ERROR,
-				(errmsg("%s", strip_trailing_ws(SvPV(ERRSV, PL_na)))));
+				(errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV)))));
 	}
 
 	retval = newSVsv(POPs);
@@ -1467,8 +1477,8 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 			perlret = array_ret;
 		}
 
-		val = SvPV(perlret, PL_na);
-
+		val = SvPV_nolen(perlret);
+		pg_verifymbstr(val, strlen(val), false);
 		retval = InputFunctionCall(&prodesc->result_in_func, val,
 								   prodesc->result_typioparam, -1);
 	}
@@ -1550,7 +1560,7 @@ plperl_trigger_handler(PG_FUNCTION_ARGS)
 		HeapTuple	trv;
 		char	   *tmp;
 
-		tmp = SvPV(perlret, PL_na);
+		tmp = SvPV_nolen(perlret);
 
 		if (pg_strcasecmp(tmp, "SKIP") == 0)
 			trv = NULL;
@@ -2124,8 +2134,8 @@ plperl_return_next(SV *sv)
 				sv = plperl_convert_to_pg_array(sv);
 			}
 
-			val = SvPV(sv, PL_na);
-
+			val = SvPV_nolen(sv);
+			pg_verifymbstr(val, strlen(val), false);
 			ret = InputFunctionCall(&prodesc->result_in_func, val,
 									prodesc->result_typioparam, -1);
 			isNull = false;
@@ -2357,7 +2367,7 @@ plperl_spi_prepare(char *query, int argc, SV **argv)
 						typIOParam;
 			int32		typmod;
 
-			parseTypeString(SvPV(argv[i], PL_na), &typId, &typmod);
+			parseTypeString(SvPV_nolen(argv[i]), &typId, &typmod);
 
 			getTypeInputInfo(typId, &typInput, &typIOParam);
 
@@ -2516,8 +2526,12 @@ plperl_spi_exec_prepared(char *query, HV *attr, int argc, SV **argv)
 		{
 			if (SvOK(argv[i]))
 			{
+				char *val;
+
+				val = SvPV_nolen(argv[i]);
+				pg_verifymbstr(val, strlen(val), false);
 				argvalues[i] = InputFunctionCall(&qdesc->arginfuncs[i],
-												 SvPV(argv[i], PL_na),
+												 val,
 												 qdesc->argtypioparams[i],
 												 -1);
 				nulls[i] = ' ';
@@ -2647,8 +2661,12 @@ plperl_spi_query_prepared(char *query, int argc, SV **argv)
 		{
 			if (SvOK(argv[i]))
 			{
+				char *val;
+				
+				val = SvPV_nolen(argv[i]);
+				pg_verifymbstr(val, strlen(val), false);
 				argvalues[i] = InputFunctionCall(&qdesc->arginfuncs[i],
-												 SvPV(argv[i], PL_na),
+												 val,
 												 qdesc->argtypioparams[i],
 												 -1);
 				nulls[i] = ' ';