From aadcc5c31df00e940a89abf392e7c71b54e00b6a Mon Sep 17 00:00:00 2001
From: Marti Raudsepp <marti@juffo.org>
Date: Sat, 30 Oct 2010 01:27:06 +0300
Subject: [PATCH 1/2] Cleanup: Simplify comparisons (a - b == 0) to (a == b)

This change was done using Coccinelle using the following spatch:

virtual org,diff
@@
expression a, b;
@@
(
-  a - b == 0
+  a == b
|
-  a - b != 0
+  a != b
)

Marti Raudsepp
---
 contrib/pgcrypto/crypt-des.c         |    4 ++--
 src/backend/access/gin/gindatapage.c |    4 ++--
 src/backend/regex/regc_lex.c         |    2 +-
 src/timezone/zic.c                   |    2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/contrib/pgcrypto/crypt-des.c b/contrib/pgcrypto/crypt-des.c
index 1f49743..fc3c0e3 100644
--- a/contrib/pgcrypto/crypt-des.c
+++ b/contrib/pgcrypto/crypt-des.c
@@ -669,7 +669,7 @@ px_crypt_des(const char *key, const char *setting)
 	 * zeros.
 	 */
 	q = (uint8 *) keybuf;
-	while (q - (uint8 *) keybuf - 8)
+	while (q - (uint8 *) keybuf != 8)
 	{
 		if ((*q++ = *key << 1))
 			key++;
@@ -702,7 +702,7 @@ px_crypt_des(const char *key, const char *setting)
 			 * And XOR with the next 8 characters of the key.
 			 */
 			q = (uint8 *) keybuf;
-			while (q - (uint8 *) keybuf - 8 && *key)
+			while (q - (uint8 *) keybuf != 8 && *key)
 				*q++ ^= *key++ << 1;
 
 			if (des_setkey((char *) keybuf))
diff --git a/src/backend/access/gin/gindatapage.c b/src/backend/access/gin/gindatapage.c
index f74373c..d0873ce 100644
--- a/src/backend/access/gin/gindatapage.c
+++ b/src/backend/access/gin/gindatapage.c
@@ -285,7 +285,7 @@ GinDataPageAddItem(Page page, void *data, OffsetNumber offset)
 	else
 	{
 		ptr = GinDataPageGetItem(page, offset);
-		if (maxoff + 1 - offset != 0)
+		if (maxoff + 1 != offset)
 			memmove(ptr + GinSizeOfItem(page), ptr, (maxoff - offset + 1) * GinSizeOfItem(page));
 	}
 	memcpy(ptr, data, GinSizeOfItem(page));
@@ -494,7 +494,7 @@ dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRe
 	else
 	{
 		ptr = vector + (off - 1) * sizeofitem;
-		if (maxoff + 1 - off != 0)
+		if (maxoff + 1 != off)
 			memmove(ptr + sizeofitem, ptr, (maxoff - off + 1) * sizeofitem);
 		if (GinPageIsLeaf(lpage))
 		{
diff --git a/src/backend/regex/regc_lex.c b/src/backend/regex/regc_lex.c
index da3ff0b..3360cfb 100644
--- a/src/backend/regex/regc_lex.c
+++ b/src/backend/regex/regc_lex.c
@@ -846,7 +846,7 @@ lexescape(struct vars * v)
 			if (ISERR())
 				FAILW(REG_EESCAPE);
 			/* ugly heuristic (first test is "exactly 1 digit?") */
-			if (v->now - save == 0 || ((int) c > 0 && (int) c <= v->nsubexp))
+			if (v->now == save || ((int) c > 0 && (int) c <= v->nsubexp))
 			{
 				NOTE(REG_UBACKREF);
 				RETV(BACKREF, (chr) c);
diff --git a/src/timezone/zic.c b/src/timezone/zic.c
index 8a95d6a..694b45a 100644
--- a/src/timezone/zic.c
+++ b/src/timezone/zic.c
@@ -2780,7 +2780,7 @@ newabbr(const char *string)
 		while (isascii((unsigned char) *cp) &&
 			   isalpha((unsigned char) *cp))
 			++cp;
-		if (cp - string == 0)
+		if (cp == string)
 			wp = _("time zone abbreviation lacks alphabetic at start");
 		if (noise && cp - string > 3)
 			wp = _("time zone abbreviation has more than 3 alphabetics");
-- 
1.7.3.2