Fix typos and grammar in the code

The large majority of these have been introduced by recent commits done
in the v18 development cycle.

Author: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/9a7763ab-5252-429d-a943-b28941e0e28b@gmail.com

3 files changed, 9 insertions, 9 deletions

diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c
index cfab93ec30c..a7b7b5996e3 100644
--- a/src/backend/access/gin/gininsert.c
+++ b/src/backend/access/gin/gininsert.c
@@ -167,7 +167,7 @@ typedef struct
 
 	/*
 	 * The sortstate used only within a single worker for the first merge pass
-	 * happenning there. In principle it doesn't need to be part of the build
+	 * happening there. In principle it doesn't need to be part of the build
 	 * state and we could pass it around directly, but it's more convenient
 	 * this way. And it's part of the build state, after all.
 	 */
@@ -1306,7 +1306,7 @@ GinBufferIsEmpty(GinBuffer *buffer)
  * Compare if the tuple matches the already accumulated data in the GIN
  * buffer. Compare scalar fields first, before the actual key.
  *
- * Returns true if the key matches, and the TID belonds to the buffer, or
+ * Returns true if the key matches, and the TID belongs to the buffer, or
  * false if the key does not match.
  */
 static bool
@@ -1497,7 +1497,7 @@ GinBufferStoreTuple(GinBuffer *buffer, GinTuple *tup)
 			buffer->items = repalloc(buffer->items,
 									 (buffer->nitems + tup->nitems) * sizeof(ItemPointerData));
 
-		new = ginMergeItemPointers(&buffer->items[buffer->nfrozen], /* first unfronzen */
+		new = ginMergeItemPointers(&buffer->items[buffer->nfrozen], /* first unfrozen */
 								   (buffer->nitems - buffer->nfrozen),	/* num of unfrozen */
 								   items, tup->nitems, &nnew);
 
@@ -1531,7 +1531,7 @@ GinBufferReset(GinBuffer *buffer)
 		pfree(DatumGetPointer(buffer->key));
 
 	/*
-	 * Not required, but makes it more likely to trigger NULL derefefence if
+	 * Not required, but makes it more likely to trigger NULL dereference if
 	 * using the value incorrectly, etc.
 	 */
 	buffer->key = (Datum) 0;
@@ -1603,7 +1603,7 @@ GinBufferCanAddKey(GinBuffer *buffer, GinTuple *tup)
  *
  * After waiting for all workers to finish, merge the per-worker results into
  * the complete index. The results from each worker are sorted by block number
- * (start of the page range). While combinig the per-worker results we merge
+ * (start of the page range). While combining the per-worker results we merge
  * summaries for the same page range, and also fill-in empty summaries for
  * ranges without any tuples.
  *
diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index f69397623df..77264ddeecb 100644
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -1792,7 +1792,7 @@ _bt_readpage(IndexScanDesc scan, ScanDirection dir, OffsetNumber offnum,
 
 			truncatt = BTreeTupleGetNAtts(itup, rel);
 			pstate.forcenonrequired = false;
-			pstate.startikey = 0;	/* _bt_set_startikey ignores HIKEY */
+			pstate.startikey = 0;	/* _bt_set_startikey ignores P_HIKEY */
 			_bt_checkkeys(scan, &pstate, arrayKeys, itup, truncatt);
 		}
 
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index ec40c0b7c42..2d4c346473b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -473,7 +473,7 @@ typedef struct XLogCtlData
 	XLogRecPtr	InitializedFrom;
 
 	/*
-	 * Latest reserved for inititalization page in the cache (last byte
+	 * Latest reserved for initialization page in the cache (last byte
 	 * position + 1).
 	 *
 	 * To change the identity of a buffer, you need to advance
@@ -2221,7 +2221,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
 		 *	  m must observe f[k] == false.  Otherwise, it will later attempt
 		 *	  CAS(v, k, k + 1) with success.
 		 * 4. Therefore, corresponding read_barrier() (while j == k) on
-		 *	  process m happend before write_barrier() of process k.  But then
+		 *	  process m reached before write_barrier() of process k.  But then
 		 *	  process k attempts CAS(v, k, k + 1) after process m successfully
 		 *	  incremented v to k, and that CAS operation must succeed.
 		 *	  That leads to a contradiction.  So, there is no such k (k < n)
@@ -2253,7 +2253,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
 			if (pg_atomic_read_u64(&XLogCtl->xlblocks[nextidx]) != NewPageEndPtr)
 			{
 				/*
-				 * Page at nextidx wasn't initialized yet, so we cann't move
+				 * Page at nextidx wasn't initialized yet, so we can't move
 				 * InitializedUpto further. It will be moved by backend which
 				 * will initialize nextidx.
 				 */