Eric Pouech : server: Allow 0-write length in WriteProcessMemory().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 9897719562fc47d8d3476928d3db0dd5eb6dfb28
URL:    https://gitlab.winehq.org/wine/wine/-/commit/9897719562fc47d8d3476928d3db0dd...

Author: Eric Pouech <epouech(a)codeweavers.com>
Date:   Mon Feb 26 12:12:50 2024 +0100

server: Allow 0-write length in WriteProcessMemory().

Adapt to Win >= 10 behavior.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56357
Signed-off-by: Eric Pouech <epouech(a)codeweavers.com>

---

 dlls/kernel32/tests/virtual.c | 8 ++++++++
 server/process.c              | 1 -
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/dlls/kernel32/tests/virtual.c b/dlls/kernel32/tests/virtual.c
index c54fb16ba15..a023104ad88 100644
--- a/dlls/kernel32/tests/virtual.c
+++ b/dlls/kernel32/tests/virtual.c
@@ -114,6 +114,14 @@ static void test_VirtualAllocEx(void)
     ok(b && (bytes_read == alloc_size), "%Iu bytes read\n", bytes_read);
     ok(!memcmp(src, dst, alloc_size), "Data from remote process differs\n");
 
+    /* test 0 length */
+    bytes_written = 0xdeadbeef;
+    b = WriteProcessMemory(hProcess, addr1, src, 0, &bytes_written);
+    ok((b && !bytes_written) || broken(!b && GetLastError() == ERROR_INVALID_PARAMETER), "write failed: %lu\n", GetLastError());
+    bytes_read = 0xdeadbeef;
+    b = ReadProcessMemory(hProcess, addr1, src, 0, &bytes_read);
+    ok(b && !bytes_read, "read failed: %lu\n", GetLastError());
+
     /* test invalid source buffers */
 
     b = VirtualProtect( src + 0x2000, 0x2000, PAGE_NOACCESS, &old_prot );
diff --git a/server/process.c b/server/process.c
index b6c21d15752..349aa87be3d 100644
--- a/server/process.c
+++ b/server/process.c
@@ -1659,7 +1659,6 @@ DECL_HANDLER(write_process_memory)
     {
         data_size_t len = get_req_data_size();
         if (len) write_process_memory( process, req->addr, len, get_req_data() );
-        else set_error( STATUS_INVALID_PARAMETER );
         release_object( process );
     }
 }