Francois Gouget : mscoree/tests: Avoid temporary directory name collisions.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: c11e923422f40ab0ee5e512d81cb14c85faff6a5
URL:    https://gitlab.winehq.org/wine/wine/-/commit/c11e923422f40ab0ee5e512d81cb14c...

Author: Francois Gouget 
Date:   Sun Mar 19 20:07:33 2023 +0100

mscoree/tests: Avoid temporary directory name collisions.

test_loadpaths_execute() was sometimes getting ERROR_ALREADY_EXISTS when
creating its temporary directoryi. That was probably because
GetTempFileNameW() only uses the low 16-bits of the 'random' LUID which
goes over a wider range, potentially leading to collisions in the lower
16-bits.
Avoid AllocateLocallyUniqueId() entirely and add a helper function to
create a guaranteed new directory.
Also try to use the current directory first as it is assumed to have
been configured to ward off anti-virus programs (specifically
Microsoft Defender) which is especially important when writing
executables to that location. Only switch to the system's temporary
directory if the current directory is not a writable location.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54560

---

dlls/mscoree/tests/mscoree.c | 55 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 13 deletions(-)

diff --git a/dlls/mscoree/tests/mscoree.c b/dlls/mscoree/tests/mscoree.c
index e5065a41d88..adac72e5f4c 100644
--- a/dlls/mscoree/tests/mscoree.c
+++ b/dlls/mscoree/tests/mscoree.c
@@ -592,25 +592,55 @@ static BOOL compile_cs(const WCHAR *source, const WCHAR *target, const WCHAR *ty
     return ret;
 }

+static BOOL create_new_dir(WCHAR newdir[MAX_PATH], const WCHAR* parent,
+                           const WCHAR* prefix)
+{
+    WCHAR path[MAX_PATH];
+    BOOL try_tmpdir = TRUE;
+    static unsigned i = 0;
+
+    if (!parent)
+    {
+        GetCurrentDirectoryW(ARRAY_SIZE(path), path);
+        parent = path;
+    }
+    while (1)
+    {
+        swprintf(newdir, MAX_PATH, L"%s\%s%04d", path, prefix, i);
+        if (CreateDirectoryW(newdir, NULL))
+            return TRUE;
+        switch (GetLastError())
+        {
+        case ERROR_ACCESS_DENIED:
+            if (!try_tmpdir)
+                return FALSE;
+            try_tmpdir = FALSE;
+            GetTempPathW(ARRAY_SIZE(path), path);
+            path[wcslen(path) - 1] = 0; /* redundant trailing backslash */
+            parent = path;
+            break;
+        case ERROR_ALREADY_EXISTS:
+            i++;
+            break;
+        default:
+            return FALSE;
+        }
+    }
+}
+
 static void test_loadpaths_execute(const WCHAR *exe_name, const WCHAR *dll_name, const WCHAR *cfg_name,
                                    const WCHAR *dll_dest, BOOL expect_failure, BOOL todo)
 {
-    WCHAR tmp[MAX_PATH], tmpdir[MAX_PATH], tmpexe[MAX_PATH], tmpcfg[MAX_PATH], tmpdll[MAX_PATH];
+    WCHAR tmpdir[MAX_PATH], tmpexe[MAX_PATH], tmpcfg[MAX_PATH], tmpdll[MAX_PATH];
     PROCESS_INFORMATION pi;
     STARTUPINFOW si = { 0 };
     WCHAR *ptr, *end;
     DWORD exit_code = 0xdeadbeef;
-    LUID id;
     BOOL ret;

-    GetTempPathW(MAX_PATH, tmp);
-    ret = AllocateLocallyUniqueId(&id);
-    ok(ret, "AllocateLocallyUniqueId failed: %lu\n", GetLastError());
-    ret = GetTempFileNameW(tmp, L"loadpaths", id.LowPart, tmpdir);
-    ok(ret, "GetTempFileNameW failed: %lu\n", GetLastError());
-
-    ret = CreateDirectoryW(tmpdir, NULL);
-    ok(ret, "CreateDirectoryW(%s) failed: %lu\n", debugstr_w(tmpdir), GetLastError());
+    ok(create_new_dir(tmpdir, NULL, L"loadpaths"),
+       "failed to create a new dir %lu\n", GetLastError());
+    end = tmpdir + wcslen(tmpdir);

wcscpy(tmpexe, tmpdir);
     PathAppendW(tmpexe, exe_name);
@@ -673,9 +703,8 @@ static void test_loadpaths_execute(const WCHAR *exe_name, const WCHAR *dll_name,
     ret = DeleteFileW(tmpexe);
     ok(ret, "DeleteFileW(%s) failed: %lu\n", debugstr_w(tmpexe), GetLastError());

-    end = tmpdir + wcslen(tmp);
-    ptr = tmpdir + wcslen(tmpdir) - 1;
-    while (ptr > end && (ptr = wcsrchr(tmpdir, '\')))
+    ptr = end;
+    while (ptr >= end && (ptr = wcsrchr(tmpdir, '\')))
     {
         ret = RemoveDirectoryW(tmpdir);
         ok(ret, "RemoveDirectoryW(%s) failed: %lu\n", debugstr_w(tmpdir), GetLastError());