Fix some shadow variables in src/backend/replication/

The code is able to compile already without warnings under
-Wshadow=compatible-local, which is itself already enabled in the tree,
and the ones fixed here showed up with the more restrictive -Wshadow.

There are more of these that we may want to look at, and the ones fixed
here made the code confusing.

Author: Peter Smith
Discussion: https://postgr.es/m/CAHut+PuR0y4ofNOxi691VTVWmBfScHV9AaBMGSpeh8+DKp81Nw@mail.gmail.com

src/backend/replication/logical/logicalfuncs.c

@@ -181,10 +181,10 @@ pg_logical_slot_get_changes_guts(FunctionCallInfo fcinfo, bool confirm, bool bin
 
 		for (i = 0; i < nelems; i += 2)
 		{
-			char	   *name = TextDatumGetCString(datum_opts[i]);
+			char	   *optname = TextDatumGetCString(datum_opts[i]);
 			char	   *opt = TextDatumGetCString(datum_opts[i + 1]);
 
-			options = lappend(options, makeDefElem(name, (Node *) makeString(opt), -1));
+			options = lappend(options, makeDefElem(optname, (Node *) makeString(opt), -1));
 		}
 	}
 

src/backend/replication/logical/reorderbuffer.c

@@ -4840,16 +4840,16 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
 		/* stitch toast tuple back together from its parts */
 		dlist_foreach(it, &ent->chunks)
 		{
-			bool		isnull;
+			bool		cisnull;
 			ReorderBufferChange *cchange;
 			ReorderBufferTupleBuf *ctup;
 			Pointer		chunk;
 
 			cchange = dlist_container(ReorderBufferChange, node, it.cur);
 			ctup = cchange->data.tp.newtuple;
-			chunk = DatumGetPointer(fastgetattr(&ctup->tuple, 3, toast_desc, &isnull));
+			chunk = DatumGetPointer(fastgetattr(&ctup->tuple, 3, toast_desc, &cisnull));
 
-			Assert(!isnull);
+			Assert(!cisnull);
 			Assert(!VARATT_IS_EXTERNAL(chunk));
 			Assert(!VARATT_IS_SHORT(chunk));
 

src/backend/replication/walsender.c

@@ -3540,7 +3540,7 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 	for (i = 0; i < max_wal_senders; i++)
 	{
 		WalSnd	   *walsnd = &WalSndCtl->walsnds[i];
-		XLogRecPtr	sentPtr;
+		XLogRecPtr	sent_ptr;
 		XLogRecPtr	write;
 		XLogRecPtr	flush;
 		XLogRecPtr	apply;
@@ -3564,7 +3564,7 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 			continue;
 		}
 		pid = walsnd->pid;
-		sentPtr = walsnd->sentPtr;
+		sent_ptr = walsnd->sentPtr;
 		state = walsnd->state;
 		write = walsnd->write;
 		flush = walsnd->flush;
@@ -3607,9 +3607,9 @@ pg_stat_get_wal_senders(PG_FUNCTION_ARGS)
 		{
 			values[1] = CStringGetTextDatum(WalSndGetStateString(state));
 
-			if (XLogRecPtrIsInvalid(sentPtr))
+			if (XLogRecPtrIsInvalid(sent_ptr))
 				nulls[2] = true;
-			values[2] = LSNGetDatum(sentPtr);
+			values[2] = LSNGetDatum(sent_ptr);
 
 			if (XLogRecPtrIsInvalid(write))
 				nulls[3] = true;