From adbbc1377a0b39cf47d2c96f75916431f6eeed9f Mon Sep 17 00:00:00 2001
From: rdb <git@rdb.name>
Date: Thu, 8 Apr 2021 12:07:00 +0200
Subject: [PATCH] dtoolutil: Work around odd Linux bug with lseek on a
 directory fd

Fixes #1140
---
 src/dtoolutil/pandaFileStreamBuf.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/dtoolutil/pandaFileStreamBuf.cxx b/src/dtoolutil/pandaFileStreamBuf.cxx
index 676f17e0e66..1caecaf9917 100644
--- a/src/dtoolutil/pandaFileStreamBuf.cxx
+++ b/src/dtoolutil/pandaFileStreamBuf.cxx
@@ -333,7 +333,7 @@ seekoff(streamoff off, ios_seekdir dir, ios_openmode which) {
       // Posix case.
       {
         off_t li = lseek(_fd, off, SEEK_END);
-        if (li == (off_t)-1) {
+        if (li == (off_t)-1 || (sizeof(off_t) == 8 && li == 0x7fffffffffffffff)) {
           return -1;
         }
         new_pos = (size_t)li;