From 39ef78f8b21f02f94cbda148be1a3e9770223c7b Mon Sep 17 00:00:00 2001
From: Joshua Davies <joshua.davies@kit.edu>
Date: Sun, 5 Aug 2018 18:36:08 +0200
Subject: [PATCH] Avoid possible performance issue

Only check total size if in error condition.
---
 sources/sort.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/sources/sort.c b/sources/sort.c
index a095d1b2..8d7d3c96 100644
--- a/sources/sort.c
+++ b/sources/sort.c
@@ -681,7 +681,7 @@ LONG EndSort(PHEAD WORD *buffer, int par)
 {
   GETBIDENTITY
   SORTING *S = AT.SS;
-  WORD j, **ss, **tmpss, *to, *t;
+  WORD j, **ss, *to, *t;
   LONG sSpace, over, tover, spare, retval = 0, jj;
   POSITION position, pp;
   off_t lSpace;
@@ -775,24 +775,21 @@ LONG EndSort(PHEAD WORD *buffer, int par)
 				retval = sSpace + 1;
 			}
 			else {
-				/* First check if the sorted argument fits in AM.MaxTer. */
-				sSpace = 0;
-				tmpss = ss;
-				while ( (t = *tmpss++) != 0 ) {
-					sSpace += *t;
-				}
-				if ( sSpace > AM.MaxTer/((LONG)sizeof(WORD)) ) {
-					MLOCK(ErrorMessageLock);
-					MesPrint("Sorted function argument too long: %d words", sSpace);
-					MesPrint("MaxTermSize: %d words", AM.MaxTer/(LONG)sizeof(WORD));
-					MUNLOCK(ErrorMessageLock);
-					retval = -1; goto RetRetval;
-				}
-				/* Now copy, it fits */
 				to = buffer;
 				sSpace = 0;
 				while ( ( t = *ss++ ) != 0 ) {
 					j = *t;
+					if ( ( sSpace += j ) > AM.MaxTer/((LONG)sizeof(WORD)) ) {
+						/* Too big! Get the total size for useful error message */
+						while ( ( t = *ss++ ) != 0 ) {
+							sSpace += *t;
+						}
+						MLOCK(ErrorMessageLock);
+						MesPrint("Sorted function argument too long: %d words", sSpace);
+						MesPrint("MaxTermSize: %d words", AM.MaxTer/((LONG)sizeof(WORD)) );
+						MUNLOCK(ErrorMessageLock);
+						retval = -1; goto RetRetval;
+					}
 					while ( --j >= 0 ) *to++ = *t++;
 				}
 				*to = 0;