Clean up more code using "(expr) ? true : false"

This is similar to fd0625c, taking care of any remaining code paths that
are worth the cleanup.  This also changes some cases using opposite
expression patterns.

Author: Justin Pryzby, Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoCdF8dnUvr-BUWWGvA_XhKSoANacBMZb6jKyCk4TYfQ2Q@mail.gmail.com

contrib/ltree/ltree_op.c

@@ -91,42 +91,42 @@ Datum
 ltree_lt(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res < 0) ? true : false);
+	PG_RETURN_BOOL(res < 0);
 }
 
 Datum
 ltree_le(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res <= 0) ? true : false);
+	PG_RETURN_BOOL(res <= 0);
 }
 
 Datum
 ltree_eq(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res == 0) ? true : false);
+	PG_RETURN_BOOL(res == 0);
 }
 
 Datum
 ltree_ge(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res >= 0) ? true : false);
+	PG_RETURN_BOOL(res >= 0);
 }
 
 Datum
 ltree_gt(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res > 0) ? true : false);
+	PG_RETURN_BOOL(res > 0);
 }
 
 Datum
 ltree_ne(PG_FUNCTION_ARGS)
 {
 	RUNCMP;
-	PG_RETURN_BOOL((res != 0) ? true : false);
+	PG_RETURN_BOOL(res != 0);
 }
 
 Datum

src/backend/access/gist/gistsplit.c

@@ -421,8 +421,8 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, int attno, GistSplitVec
 	 * Prepare spl_ldatum/spl_rdatum/spl_ldatum_exists/spl_rdatum_exists in
 	 * case we are doing a secondary split (see comments in gist.h).
 	 */
-	sv->spl_ldatum_exists = (v->spl_lisnull[attno]) ? false : true;
-	sv->spl_rdatum_exists = (v->spl_risnull[attno]) ? false : true;
+	sv->spl_ldatum_exists = !(v->spl_lisnull[attno]);
+	sv->spl_rdatum_exists = !(v->spl_risnull[attno]);
 	sv->spl_ldatum = v->spl_lattr[attno];
 	sv->spl_rdatum = v->spl_rattr[attno];
 
@@ -451,8 +451,8 @@ gistUserPicksplit(Relation r, GistEntryVector *entryvec, int attno, GistSplitVec
 		 * Reinit GIST_SPLITVEC. Although these fields are not used by
 		 * genericPickSplit(), set them up for further processing
 		 */
-		sv->spl_ldatum_exists = (v->spl_lisnull[attno]) ? false : true;
-		sv->spl_rdatum_exists = (v->spl_risnull[attno]) ? false : true;
+		sv->spl_ldatum_exists = !(v->spl_lisnull[attno]);
+		sv->spl_rdatum_exists = !(v->spl_risnull[attno]);
 		sv->spl_ldatum = v->spl_lattr[attno];
 		sv->spl_rdatum = v->spl_rattr[attno];
 

src/backend/commands/tablecmds.c

@@ -7463,7 +7463,7 @@ ATExecColumnDefault(Relation rel, const char *colName,
 	 * operation when the user asked for a drop.
 	 */
 	RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
-					  newDefault == NULL ? false : true);
+					  newDefault != NULL);
 
 	if (newDefault)
 	{

src/backend/executor/nodeResult.c

@@ -195,7 +195,7 @@ ExecInitResult(Result *node, EState *estate, int eflags)
 	resstate->ps.ExecProcNode = ExecResult;
 
 	resstate->rs_done = false;
-	resstate->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
+	resstate->rs_checkqual = (node->resconstantqual != NULL);
 
 	/*
 	 * Miscellaneous initialization
@@ -260,7 +260,7 @@ void
 ExecReScanResult(ResultState *node)
 {
 	node->rs_done = false;
-	node->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
+	node->rs_checkqual = (node->resconstantqual != NULL);
 
 	/*
 	 * If chgParam of subnode is not null then plan will be re-scanned by

src/backend/statistics/mcv.c

@@ -1619,8 +1619,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 	Assert(mcvlist->nitems <= STATS_MCVLIST_MAX_ITEMS);
 
 	matches = palloc(sizeof(bool) * mcvlist->nitems);
-	memset(matches, (is_or) ? false : true,
-		   sizeof(bool) * mcvlist->nitems);
+	memset(matches, !is_or,  sizeof(bool) * mcvlist->nitems);
 
 	/*
 	 * Loop through the list of clauses, and for each of them evaluate all the

src/backend/tsearch/ts_utils.c

@@ -142,5 +142,5 @@ searchstoplist(StopList *s, char *key)
 {
 	return (s->stop && s->len > 0 &&
 			bsearch(&key, s->stop, s->len,
-					sizeof(char *), pg_qsort_strcmp)) ? true : false;
+					sizeof(char *), pg_qsort_strcmp));
 }

src/backend/tsearch/wparser_def.c

@@ -1856,7 +1856,7 @@ TParserGet(TParser *prs)
 		}
 	}
 
-	return (item && (item->flags & A_BINGO)) ? true : false;
+	return (item && (item->flags & A_BINGO));
 }
 
 Datum