Fix ts_stat's failure on empty tsvector.

tglsfdc · tglsfdc · commit b14071164366 · 2009-10-13T14:33:14.000Z
Also insert a couple of Asserts that check for stack overflow.
Bogus coding appears to be new in 8.4 --- older releases had a much
simpler algorithm here.  Per bug #5111.
diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/tsvector_op.c,v 1.24 2009/07/16 06:33:44 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/tsvector_op.c,v 1.25 2009/10/13 14:33:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -959,17 +959,21 @@ ts_setup_firstcall(FunctionCallInfo fcinfo, FuncCallContext *funcctx,
 
 	node = stat->root;
 	/* find leftmost value */
-	for (;;)
-	{
-		stat->stack[stat->stackpos] = node;
-		if (node->left)
+	if (node == NULL)
+		stat->stack[stat->stackpos] = NULL;
+	else
+		for (;;)
 		{
-			stat->stackpos++;
-			node = node->left;
+			stat->stack[stat->stackpos] = node;
+			if (node->left)
+			{
+				stat->stackpos++;
+				node = node->left;
+			}
+			else
+				break;
 		}
-		else
-			break;
-	}
+	Assert(stat->stackpos <= stat->maxdepth);
 
 	tupdesc = CreateTemplateTupleDesc(3, false);
 	TupleDescInitEntry(tupdesc, (AttrNumber) 1, "word",
@@ -1015,6 +1019,7 @@ walkStatEntryTree(TSVectorStat *stat)
 			else
 				break;
 		}
+		Assert(stat->stackpos <= stat->maxdepth);
 	}
 	else
 	{

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@`
`7`	`7`	`*`
`8`	`8`	`*`
`9`	`9`	`* IDENTIFICATION`
`10`		`- * $PostgreSQL: pgsql/src/backend/utils/adt/tsvector_op.c,v 1.24 2009/07/16 06:33:44 petere Exp $`
	`10`	`+ * $PostgreSQL: pgsql/src/backend/utils/adt/tsvector_op.c,v 1.25 2009/10/13 14:33:14 tgl Exp $`
`11`	`11`	`*`
`12`	`12`	`*-------------------------------------------------------------------------`
`13`	`13`	`*/`
`@@ -959,17 +959,21 @@ ts_setup_firstcall(FunctionCallInfo fcinfo, FuncCallContext *funcctx,`
`959`	`959`
`960`	`960`	`node = stat->root;`
`961`	`961`	`/* find leftmost value */`
`962`		`- for (;;)`
`963`		`- {`
`964`		`- stat->stack[stat->stackpos] = node;`
`965`		`- if (node->left)`
	`962`	`+ if (node == NULL)`
	`963`	`+ stat->stack[stat->stackpos] = NULL;`
	`964`	`+ else`
	`965`	`+ for (;;)`
`966`	`966`	`{`
`967`		`- stat->stackpos++;`
`968`		`- node = node->left;`
	`967`	`+ stat->stack[stat->stackpos] = node;`
	`968`	`+ if (node->left)`
	`969`	`+ {`
	`970`	`+ stat->stackpos++;`
	`971`	`+ node = node->left;`
	`972`	`+ }`
	`973`	`+ else`
	`974`	`+ break;`
`969`	`975`	`}`
`970`		`- else`
`971`		`- break;`
`972`		`- }`
	`976`	`+ Assert(stat->stackpos <= stat->maxdepth);`
`973`	`977`
`974`	`978`	`tupdesc = CreateTemplateTupleDesc(3, false);`
`975`	`979`	`TupleDescInitEntry(tupdesc, (AttrNumber) 1, "word",`
`@@ -1015,6 +1019,7 @@ walkStatEntryTree(TSVectorStat *stat)`
`1015`	`1019`	`else`
`1016`	`1020`	`break;`
`1017`	`1021`	`}`
	`1022`	`+ Assert(stat->stackpos <= stat->maxdepth);`
`1018`	`1023`	`}`
`1019`	`1024`	`else`
`1020`	`1025`	`{`