Am 03.08.2022 um 19:20 schrieb Jeff King:

On Wed, Aug 03, 2022 at 06:45:23PM +0200, René Scharfe wrote:

quoted

quoted

+test_expect_success 'handle very large filtered diff' '
+	git reset --hard &&
+	# The specific number here is not important, but it must
+	# be large enough that the output of "git diff --color"
+	# fills up the pipe buffer. 10,000 results in ~200k of
+	# colored output.
+	test_seq 10000 >test &&
+	false &&

Isn't this test going to end here, reporting failure before it even gets
to the interesting part?

Urgh, whoops. That was from some last-minute tweaking of the comment.
There was also a line:

  git diff --color | wc -c

before it so I could measure how big the output was for a few values.

It snuck into the emailed patch, but the actual test runs (including the
Windows CI) didn't include that (since obviously they'd have failed the
test).

Without that line the added test hangs for me on the Git for Windows
SDK on Windows 11.

With the patch below it fails and reports basically nothing:

   expecting success of 3701.57 'handle very large filtered diff':
           git reset --hard &&
           # The specific number here is not important, but it must
           # be large enough that the output of "git diff --color"
           # fills up the pipe buffer. 10,000 results in ~200k of
           # colored output.
           test_seq 10000 >test &&
           test_config interactive.diffFilter cat &&
           printf y >y &&
           force_color git add -p >output 2>&1 <y &&
           git diff-files --exit-code -- test

   HEAD is now at 095e8c6 main
   not ok 57 - handle very large filtered diff
   #
   #               git reset --hard &&
   #               # The specific number here is not important, but it must
   #               # be large enough that the output of "git diff --color"
   #               # fills up the pipe buffer. 10,000 results in ~200k of
   #               # colored output.
   #               test_seq 10000 >test &&
   #               test_config interactive.diffFilter cat &&
   #               printf y >y &&
   #               force_color git add -p >output 2>&1 <y &&
   #               git diff-files --exit-code -- test
   #
   1..57

The file "output" contains "error: failed to run 'cat'".  This is
add-patch.c::parse_diff() reporting that pipe_command() failed.  So
that's not it, yet.  (I don't actually know what I'm doing here.)

---
 compat/nonblock.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/compat/nonblock.c b/compat/nonblock.c
index 897c099010..030cf92af2 100644
--- a/compat/nonblock.c
+++ b/compat/nonblock.c

@@ -14,8 +14,21 @@ int enable_nonblock(int fd)

 #else

+#include "win32.h"
+
 int enable_nonblock(int fd)
 {
+	DWORD mode;
+	HANDLE handle = winansi_get_osfhandle(fd);
+	if (!handle)
+		return -1;
+	if (!GetNamedPipeHandleState(handle, &mode, NULL, NULL, NULL, NULL, 0))
+		return -1;
+	if (mode & PIPE_NOWAIT)
+		return 0;
+	mode |= PIPE_NOWAIT;
+	if (!SetNamedPipeHandleState(handle, &mode, NULL, NULL))
+		return -1;
 	return 0;
 }

--

2.37.1.windows.1