Use memmove() instead of memcpy() for copying overlapping regions.

hlinnaka · hlinnaka · commit 5f778e6444c8 · 2014-02-10T10:00:23.000+02:00
In commit d2495f2, I fixed this bug in to_tsquery(), but missed the fact that plainto_tsquery() has the same bug.
diff --git a/src/backend/tsearch/to_tsany.c b/src/backend/tsearch/to_tsany.c
@@ -398,6 +398,7 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)
 	if (query->size == 0)
 		PG_RETURN_TSQUERY(query);
 
+	/* clean out any stopword placeholders from the tree */
 	res = clean_fakeval(GETQUERY(query), &len);
 	if (!res)
 	{
@@ -407,6 +408,10 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)
 	}
 	memcpy((void *) GETQUERY(query), (void *) res, len * sizeof(QueryItem));
 
+	/*
+	 * Removing the stopword placeholders might've resulted in fewer
+	 * QueryItems. If so, move the operands up accordingly.
+	 */
 	if (len != query->size)
 	{
 		char	   *oldoperand = GETOPERAND(query);
@@ -415,7 +420,7 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)
 		Assert(len < query->size);
 
 		query->size = len;
-		memcpy((void *) GETOPERAND(query), oldoperand, lenoperand);
+		memmove((void *) GETOPERAND(query), oldoperand, lenoperand);
 		SET_VARSIZE(query, COMPUTESIZE(len, lenoperand));
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -398,6 +398,7 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)`
`398`	`398`	`if (query->size == 0)`
`399`	`399`	`PG_RETURN_TSQUERY(query);`
`400`	`400`
	`401`	`+ /* clean out any stopword placeholders from the tree */`
`401`	`402`	`res = clean_fakeval(GETQUERY(query), &len);`
`402`	`403`	`if (!res)`
`403`	`404`	`{`
`@@ -407,6 +408,10 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)`
`407`	`408`	`}`
`408`	`409`	`memcpy((void ) GETQUERY(query), (void ) res, len * sizeof(QueryItem));`
`409`	`410`
	`411`	`+ /*`
	`412`	`+ * Removing the stopword placeholders might've resulted in fewer`
	`413`	`+ * QueryItems. If so, move the operands up accordingly.`
	`414`	`+ */`
`410`	`415`	`if (len != query->size)`
`411`	`416`	`{`
`412`	`417`	`char *oldoperand = GETOPERAND(query);`
`@@ -415,7 +420,7 @@ plainto_tsquery_byid(PG_FUNCTION_ARGS)`
`415`	`420`	`Assert(len < query->size);`
`416`	`421`
`417`	`422`	`query->size = len;`
`418`		`- memcpy((void *) GETOPERAND(query), oldoperand, lenoperand);`
	`423`	`+ memmove((void *) GETOPERAND(query), oldoperand, lenoperand);`
`419`	`424`	`SET_VARSIZE(query, COMPUTESIZE(len, lenoperand));`
`420`	`425`	`}`
`421`	`426`