diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 8253ced0c5..d62cbdce32 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -80,8 +80,8 @@ typedef struct
 	char	   *buf1;			/* 1st string, or abbreviation original string
 								 * buf */
 	char	   *buf2;			/* 2nd string, or abbreviation strxfrm() buf */
-	int			buflen1;
-	int			buflen2;
+	int			buflen1;		/* Allocated length of buf1 */
+	int			buflen2;		/* Allocated length of buf2 */
 	int			last_len1;		/* Length of last buf1 string/strxfrm() input */
 	int			last_len2;		/* Length of last buf2 string/strxfrm() blob */
 	int			last_returned;	/* Last comparison result (cache) */
@@ -2340,15 +2340,13 @@ varstrfastcmp_locale(char *a1p, int len1, char *a2p, int len2, SortSupport ssup)
 
 	if (len1 >= sss->buflen1)
 	{
-		pfree(sss->buf1);
 		sss->buflen1 = Max(len1 + 1, Min(sss->buflen1 * 2, MaxAllocSize));
-		sss->buf1 = MemoryContextAlloc(ssup->ssup_cxt, sss->buflen1);
+		sss->buf1 = repalloc(sss->buf1, sss->buflen1);
 	}
 	if (len2 >= sss->buflen2)
 	{
-		pfree(sss->buf2);
 		sss->buflen2 = Max(len2 + 1, Min(sss->buflen2 * 2, MaxAllocSize));
-		sss->buf2 = MemoryContextAlloc(ssup->ssup_cxt, sss->buflen2);
+		sss->buf2 = repalloc(sss->buf2, sss->buflen2);
 	}
 
 	/*
@@ -2549,9 +2547,8 @@ varstr_abbrev_convert(Datum original, SortSupport ssup)
 		/* By convention, we use buffer 1 to store and NUL-terminate */
 		if (len >= sss->buflen1)
 		{
-			pfree(sss->buf1);
 			sss->buflen1 = Max(len + 1, Min(sss->buflen1 * 2, MaxAllocSize));
-			sss->buf1 = palloc(sss->buflen1);
+			sss->buf1 = repalloc(sss->buf1, sss->buflen1);
 		}
 
 		/* Might be able to reuse strxfrm() blob from last call */
@@ -2638,10 +2635,9 @@ varstr_abbrev_convert(Datum original, SortSupport ssup)
 			/*
 			 * Grow buffer and retry.
 			 */
-			pfree(sss->buf2);
 			sss->buflen2 = Max(bsize + 1,
 							   Min(sss->buflen2 * 2, MaxAllocSize));
-			sss->buf2 = palloc(sss->buflen2);
+			sss->buf2 = repalloc(sss->buf2, sss->buflen2);
 		}
 
 		/*