This change is not necessary for the XLogRead() refactoring itself, but I
noticed the problem while working on it. Not sure it's worth a separate CF
entry.

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 9196aa3aae..8cb551a837 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -35,6 +35,7 @@ static bool ValidXLogRecordHeader(XLogReaderState *state, XLogRecPtr RecPtr,
 					  XLogRecPtr PrevRecPtr, XLogRecord *record, bool randAccess);
 static bool ValidXLogRecord(XLogReaderState *state, XLogRecord *record,
 				XLogRecPtr recptr);
+static void XLogReaderInvalReadState(XLogReaderState *state);
 static int ReadPageInternal(XLogReaderState *state, XLogRecPtr pageptr,
 				 int reqLen);
 static void report_invalid_record(XLogReaderState *state, const char *fmt,...) pg_attribute_printf(2, 3);
@@ -620,7 +621,7 @@ err:
 /*
  * Invalidate the xlogreader's read state to force a re-read.
  */
-void
+static void
 XLogReaderInvalReadState(XLogReaderState *state)
 {
 	state->readSegNo = 0;
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index f3bae0bf49..2d3c067135 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -212,9 +212,6 @@ extern struct XLogRecord *XLogReadRecord(XLogReaderState *state,
 extern bool XLogReaderValidatePageHeader(XLogReaderState *state,
 							 XLogRecPtr recptr, char *phdr);
 
-/* Invalidate read state */
-extern void XLogReaderInvalReadState(XLogReaderState *state);
-
 #ifdef FRONTEND
 extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
 #endif							/* FRONTEND */