Fix code to properly pull out shared memory key now that the

postmaster.pid file is larger than in previous major versions.
This is a bug introduced when I added lines to the file recently.

src/backend/utils/init/miscinit.c

@@ -825,16 +825,22 @@ CreateLockFile(const char *filename, bool amPostmaster,
 		 */
 		if (isDDLock)
 		{
-			char	   *ptr;
+			char	   *ptr = NULL;
 			unsigned long id1,
 						id2;
+			int lineno;
 
-			ptr = strchr(buffer, '\n');
-			if (ptr != NULL &&
-				(ptr = strchr(ptr + 1, '\n')) != NULL)
+			for (lineno = 1; lineno <= 4; lineno++)
 			{
+				if ((ptr = strchr(ptr, '\n')) == NULL)
+				{
+					elog(LOG, "bogus data in \"%s\"", DIRECTORY_LOCK_FILE);
+					break;
+				}
 				ptr++;
-				if (sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
+			}
+
+			if (ptr && sscanf(ptr, "%lu %lu", &id1, &id2) == 2)
 			{
 				if (PGSharedMemoryIsInUse(id1, id2))
 					ereport(FATAL,
@@ -849,7 +855,6 @@ CreateLockFile(const char *filename, bool amPostmaster,
 									 filename)));
 			}
 		}
-		}
 
 		/*
 		 * Looks like nobody's home.  Unlink the file and try again to create