pg_restore failed on tar-format archives if they contained large objects

(blobs) with comments, per bug #2727 from Konstantin Pelepelin.
Mea culpa for not having tested this case.
Back-patch to 8.1; prior branches don't dump blob comments at all.

src/bin/pg_dump/pg_backup_tar.c

@@ -16,7 +16,7 @@
  *
  *
  * IDENTIFICATION
- *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_tar.c,v 1.55 2006/10/04 00:30:05 momjian Exp $
+ *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_tar.c,v 1.56 2006/11/01 15:59:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -701,6 +701,7 @@ _LoadBlobs(ArchiveHandle *AH, RestoreOptions *ropt)
 	lclContext *ctx = (lclContext *) AH->formatData;
 	TAR_MEMBER *th;
 	size_t		cnt;
+	bool		foundBlob = false;
 	char		buf[4096];
 
 	StartRestoreBlobs(AH);
@@ -725,10 +726,22 @@ _LoadBlobs(ArchiveHandle *AH, RestoreOptions *ropt)
 					ahwrite(buf, 1, cnt, AH);
 				}
 				EndRestoreBlob(AH, oid);
+				foundBlob = true;
 			}
+			tarClose(AH, th);
+		}
+		else
+		{
+			tarClose(AH, th);
+			/*
+			 * Once we have found the first blob, stop at the first
+			 * non-blob entry (which will be 'blobs.toc').  This coding would
+			 * eat all the rest of the archive if there are no blobs ... but
+			 * this function shouldn't be called at all in that case.
+			 */
+			if (foundBlob)
+				break;
 		}
-
-		tarClose(AH, th);
 
 		th = tarOpen(AH, NULL, 'r');
 	}