From 19164929ed0887d61a4bbd3e87bd86e6a2ad8076 Mon Sep 17 00:00:00 2001
From: andri lim <jangko128@gmail.com>
Date: Sat, 17 Mar 2018 22:21:22 +0700
Subject: [PATCH] fixes #7347, asyncfile.getFileSize (#7354)

* fixes #7347

* fixes #7347
---
 lib/pure/asyncfile.nim     |  4 ++++
 tests/async/hello.txt      |  1 +
 tests/async/tasyncfile.nim | 11 +++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 tests/async/hello.txt

diff --git a/lib/pure/asyncfile.nim b/lib/pure/asyncfile.nim
index 97bec28150..1df7c3fc0e 100644
--- a/lib/pure/asyncfile.nim
+++ b/lib/pure/asyncfile.nim
@@ -78,7 +78,10 @@ proc getFileSize*(f: AsyncFile): int64 =
       raiseOSError(osLastError())
     result = (high shl 32) or low
   else:
+    let curPos = lseek(f.fd.cint, 0, SEEK_CUR)
     result = lseek(f.fd.cint, 0, SEEK_END)
+    f.offset = lseek(f.fd.cint, curPos, SEEK_SET)
+    assert(f.offset == curPos)
 
 proc newAsyncFile*(fd: AsyncFd): AsyncFile =
   ## Creates `AsyncFile` with a previously opened file descriptor `fd`.
@@ -281,6 +284,7 @@ proc read*(f: AsyncFile, size: int): Future[string] =
           result = false # We still want this callback to be called.
       elif res == 0:
         # EOF
+        f.offset = lseek(fd.cint, 0, SEEK_CUR)
         retFuture.complete("")
       else:
         readBuffer.setLen(res)
diff --git a/tests/async/hello.txt b/tests/async/hello.txt
new file mode 100644
index 0000000000..854d6c20ad
--- /dev/null
+++ b/tests/async/hello.txt
@@ -0,0 +1 @@
+hello humans!
\ No newline at end of file
diff --git a/tests/async/tasyncfile.nim b/tests/async/tasyncfile.nim
index aa7f03ab12..c7b71a2f7e 100644
--- a/tests/async/tasyncfile.nim
+++ b/tests/async/tasyncfile.nim
@@ -1,4 +1,8 @@
 discard """
+  output: '''13
+hello humans!
+13
+'''
   file: "tasyncfile.nim"
   exitcode: 0
 """
@@ -48,5 +52,12 @@ proc main() {.async.} =
     doAssert data == "t3"
     file.close()
 
+  # Issue #7347
+  block:
+    let appDir = getAppDir()
+    var file = openAsync(appDir & DirSep & "hello.txt")
+    echo file.getFileSize()
+    echo await file.readAll()
+    echo file.getFilePos()
 
 waitFor main()