From 11adefd8393a03857ff731228f94ebc3b6e96aa6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=80=9A=E6=B4=B2?= <carter.li@eoitek.com>
Date: Tue, 11 Jul 2023 19:45:16 +0800
Subject: [PATCH] Processing (Windows): fix hanging when executing cygwin
 processes

---
 src/common/processing_linux.c   |  2 +-
 src/common/processing_windows.c | 39 ++++++++++++++++++---------------
 2 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/src/common/processing_linux.c b/src/common/processing_linux.c
index 6f7dadb5e..9a97b359f 100644
--- a/src/common/processing_linux.c
+++ b/src/common/processing_linux.c
@@ -49,7 +49,7 @@ const char* ffProcessAppendOutput(FFstrbuf* buffer, char* const argv[], bool use
         }
         else if (pollfd.revents & POLLHUP)
         {
-            return "Child process closed its end (nothing to read)";
+            return NULL;
         }
     }
 
diff --git a/src/common/processing_windows.c b/src/common/processing_windows.c
index 10ca7adbf..ea304606b 100644
--- a/src/common/processing_windows.c
+++ b/src/common/processing_windows.c
@@ -82,31 +82,34 @@ const char* ffProcessAppendOutput(FFstrbuf* buffer, char* const argv[], bool use
     DWORD nRead = 0;
     OVERLAPPED overlapped = {};
     // ReadFile always completes synchronously if the pipe is not created with FILE_FLAG_OVERLAPPED
-    if (!ReadFile(hChildPipeRead, str, sizeof(str), &nRead, &overlapped))
+    do
     {
-        if (!GetOverlappedResultEx(hChildPipeRead, &overlapped, &nRead, (DWORD) timeout, TRUE))
-        {
-            if (GetLastError() == ERROR_BROKEN_PIPE)
-                return "Child process closed its end (nothing to read)";
-            CancelIo(hChildPipeRead);
-            TerminateProcess(piProcInfo.hProcess, 1);
-            return "GetOverlappedResultEx(hChildPipeRead) failed or timeout";
-        }
-    }
-    while (nRead > 0)
-    {
-        ffStrbufAppendNS(buffer, nRead, str);
         if (!ReadFile(hChildPipeRead, str, sizeof(str), &nRead, &overlapped))
         {
-            if (!GetOverlappedResult(hChildPipeRead, &overlapped, &nRead, TRUE))
+            switch (GetLastError())
             {
-                if (GetLastError() == ERROR_BROKEN_PIPE)
-                    return NULL;
+            case ERROR_IO_PENDING:
+                if (!GetOverlappedResultEx(hChildPipeRead, &overlapped, &nRead, (DWORD) timeout, TRUE))
+                {
+                    if (GetLastError() == ERROR_BROKEN_PIPE)
+                        return NULL;
+                    CancelIo(hChildPipeRead);
+                    TerminateProcess(piProcInfo.hProcess, 1);
+                    return "GetOverlappedResultEx(hChildPipeRead) failed or timeout";
+                }
+                break;
+
+            case ERROR_BROKEN_PIPE:
+                return NULL;
+
+            default:
                 CancelIo(hChildPipeRead);
-                return "GetOverlappedResult(hChildPipeRead) failed";
+                TerminateProcess(piProcInfo.hProcess, 1);
+                return "ReadFile(hChildPipeRead) failed";
             }
         }
-    }
+        ffStrbufAppendNS(buffer, nRead, str);
+    } while (nRead > 0);
 
     return NULL;
 }