Internal seeks are overoptimized. They should remember fp->_offset only for

plain regular files, i.e. files with __SOPT flag set. Fix it, so ftell(stdout)
always returns the same as lseek(1, 0, 1) now.

NOTE: this bug was in original stdio code

2 files changed, 1 insertions, 3 deletions

diff --git a/lib/libc/stdio/fopen.c b/lib/libc/stdio/fopen.c
index 709316d..84989ae 100644
--- a/lib/libc/stdio/fopen.c
+++ b/lib/libc/stdio/fopen.c
@@ -69,8 +69,6 @@ fopen(file, mode)
 	}
 	fp->_file = f;
 	fp->_flags = flags;
-	fp->_flags |= __SOFF;
-	fp->_offset = 0;
 	fp->_cookie = fp;
 	fp->_read = __sread;
 	fp->_write = __swrite;
diff --git a/lib/libc/stdio/fseek.c b/lib/libc/stdio/fseek.c
index 0cbf798..1f7ebde 100644
--- a/lib/libc/stdio/fseek.c
+++ b/lib/libc/stdio/fseek.c
@@ -344,7 +344,7 @@ _sseek(fp, offset, whence)
 		}
 		fp->_flags &= ~__SOFF;
 		ret = -1;
-	} else {
+	} else if (fp->_flags & __SOPT) {
 		fp->_flags |= __SOFF;
 		fp->_offset = ret;
 	}