Remove still more useless assignments.

Fix some more things scan-build pointed to as dead stores.  In some of
these cases, rearranging the code a little leads to more readable
code IMO.  It's all cosmetic, though.

Discussion: https://postgr.es/m/CAEudQAo1+AcGppxDSg8k+zF4+Kv+eJyqzEDdbpDg58-=MQcerQ@mail.gmail.com

src/backend/replication/slotfuncs.c

@@ -518,9 +518,6 @@ pg_logical_replication_slot_advance(XLogRecPtr moveto)
 		 */
 		XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
 
-		/* Initialize our return value in case we don't do anything */
-		retlsn = MyReplicationSlot->data.confirmed_flush;
-
 		/* invalidate non-timetravel entries */
 		InvalidateSystemCaches();
 

src/backend/utils/adt/formatting.c

@@ -6434,13 +6434,12 @@ float4_to_char(PG_FUNCTION_ARGS)
 	int			out_pre_spaces = 0,
 				sign = 0;
 	char	   *numstr,
-			   *orgnum,
 			   *p;
 
 	NUM_TOCHAR_prepare;
 
 	if (IS_ROMAN(&Num))
-		numstr = orgnum = int_to_roman((int) rint(value));
+		numstr = int_to_roman((int) rint(value));
 	else if (IS_EEEE(&Num))
 	{
 		if (isnan(value) || isinf(value))
@@ -6456,20 +6455,19 @@ float4_to_char(PG_FUNCTION_ARGS)
 		}
 		else
 		{
-			numstr = orgnum = psprintf("%+.*e", Num.post, value);
+			numstr = psprintf("%+.*e", Num.post, value);
 
 			/*
 			 * Swap a leading positive sign for a space.
 			 */
-			if (*orgnum == '+')
+			if (*numstr == '+')
-				*orgnum = ' ';
+				*numstr = ' ';
-
-			numstr = orgnum;
 		}
 	}
 	else
 	{
 		float4		val = value;
+		char	   *orgnum;
 		int			numstr_pre_len;
 
 		if (IS_MULTI(&Num))
@@ -6480,7 +6478,7 @@ float4_to_char(PG_FUNCTION_ARGS)
 			Num.pre += Num.multi;
 		}
 
-		orgnum = (char *) psprintf("%.0f", fabs(val));
+		orgnum = psprintf("%.0f", fabs(val));
 		numstr_pre_len = strlen(orgnum);
 
 		/* adjust post digits to fit max float digits */
@@ -6538,13 +6536,12 @@ float8_to_char(PG_FUNCTION_ARGS)
 	int			out_pre_spaces = 0,
 				sign = 0;
 	char	   *numstr,
-			   *orgnum,
 			   *p;
 
 	NUM_TOCHAR_prepare;
 
 	if (IS_ROMAN(&Num))
-		numstr = orgnum = int_to_roman((int) rint(value));
+		numstr = int_to_roman((int) rint(value));
 	else if (IS_EEEE(&Num))
 	{
 		if (isnan(value) || isinf(value))
@@ -6560,20 +6557,19 @@ float8_to_char(PG_FUNCTION_ARGS)
 		}
 		else
 		{
-			numstr = orgnum = (char *) psprintf("%+.*e", Num.post, value);
+			numstr = psprintf("%+.*e", Num.post, value);
 
 			/*
 			 * Swap a leading positive sign for a space.
 			 */
-			if (*orgnum == '+')
+			if (*numstr == '+')
-				*orgnum = ' ';
+				*numstr = ' ';
-
-			numstr = orgnum;
 		}
 	}
 	else
 	{
 		float8		val = value;
+		char	   *orgnum;
 		int			numstr_pre_len;
 
 		if (IS_MULTI(&Num))
@@ -6583,6 +6579,7 @@ float8_to_char(PG_FUNCTION_ARGS)
 			val = value * multi;
 			Num.pre += Num.multi;
 		}
+
 		orgnum = psprintf("%.0f", fabs(val));
 		numstr_pre_len = strlen(orgnum);
 

src/backend/utils/adt/jsonfuncs.c

@@ -4687,8 +4687,8 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 				rk1,
 				rk2;
 
-	r1 = rk1 = JsonbIteratorNext(it1, &v1, false);
+	rk1 = JsonbIteratorNext(it1, &v1, false);
-	r2 = rk2 = JsonbIteratorNext(it2, &v2, false);
+	rk2 = JsonbIteratorNext(it2, &v2, false);
 
 	/*
 	 * Both elements are objects.
@@ -4696,15 +4696,15 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 	if (rk1 == WJB_BEGIN_OBJECT && rk2 == WJB_BEGIN_OBJECT)
 	{
 		/*
-		 * Append the all tokens from v1 to res, except last WJB_END_OBJECT
+		 * Append all the tokens from v1 to res, except last WJB_END_OBJECT
 		 * (because res will not be finished yet).
 		 */
-		pushJsonbValue(state, r1, NULL);
+		pushJsonbValue(state, rk1, NULL);
 		while ((r1 = JsonbIteratorNext(it1, &v1, true)) != WJB_END_OBJECT)
 			pushJsonbValue(state, r1, &v1);
 
 		/*
-		 * Append the all tokens from v2 to res, include last WJB_END_OBJECT
+		 * Append all the tokens from v2 to res, include last WJB_END_OBJECT
 		 * (the concatenation will be completed).
 		 */
 		while ((r2 = JsonbIteratorNext(it2, &v2, true)) != WJB_DONE)
@@ -4716,7 +4716,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 	 */
 	else if (rk1 == WJB_BEGIN_ARRAY && rk2 == WJB_BEGIN_ARRAY)
 	{
-		pushJsonbValue(state, r1, NULL);
+		pushJsonbValue(state, rk1, NULL);
 
 		while ((r1 = JsonbIteratorNext(it1, &v1, true)) != WJB_END_ARRAY)
 		{
@@ -4736,10 +4736,8 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 	else if (((rk1 == WJB_BEGIN_ARRAY && !(*it1)->isScalar) && rk2 == WJB_BEGIN_OBJECT) ||
 			 (rk1 == WJB_BEGIN_OBJECT && (rk2 == WJB_BEGIN_ARRAY && !(*it2)->isScalar)))
 	{
-
 		JsonbIterator **it_array = rk1 == WJB_BEGIN_ARRAY ? it1 : it2;
 		JsonbIterator **it_object = rk1 == WJB_BEGIN_OBJECT ? it1 : it2;
-
 		bool		prepend = (rk1 == WJB_BEGIN_OBJECT);
 
 		pushJsonbValue(state, WJB_BEGIN_ARRAY, NULL);

src/bin/scripts/vacuumdb.c

@@ -408,7 +408,6 @@ vacuum_one_database(const char *dbname, vacuumingOptions *vacopts,
 	int			i;
 	int			ntups;
 	bool		failed = false;
-	bool		parallel = concurrentCons > 1;
 	bool		tables_listed = false;
 	bool		has_where = false;
 	const char *stage_commands[] = {
@@ -651,25 +650,19 @@ vacuum_one_database(const char *dbname, vacuumingOptions *vacopts,
 	PQclear(res);
 
 	/*
-	 * If there are more connections than vacuumable relations, we don't need
+	 * Ensure concurrentCons is sane.  If there are more connections than
-	 * to use them all.
+	 * vacuumable relations, we don't need to use them all.
 	 */
-	if (parallel)
-	{
 	if (concurrentCons > ntups)
 		concurrentCons = ntups;
-		if (concurrentCons <= 1)
+	if (concurrentCons <= 0)
-			parallel = false;
+		concurrentCons = 1;
-	}
 
 	/*
 	 * Setup the database connections. We reuse the connection we already have
 	 * for the first slot.  If not in parallel mode, the first slot in the
 	 * array contains the connection.
 	 */
-	if (concurrentCons <= 0)
-		concurrentCons = 1;
-
 	slots = ParallelSlotsSetup(dbname, host, port, username, prompt_password,
 							   progname, echo, conn, concurrentCons);