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Merged
encounter merged 3 commits into from
Jul 11, 2026
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Merged

add GetTempFileNameW #134

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8b88dfa
add GetTempFileNameW
miried Jul 3, 2026
2c331c0
Treat NULL `lpPrefixString` as empty string in `GetTempFileNameA` and…
miried Jul 11, 2026
3c4be9e
Fix GetTempFileName unique value truncation
miried Jul 11, 2026
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29 changes: 26 additions & 3 deletions dll/kernel32/fileapi.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1748,7 +1748,7 @@ UINT WINAPI GetTempFileNameA(LPCSTR lpPathName, LPCSTR lpPrefixString, UINT uUni
HOST_CONTEXT_GUARD();
DEBUG_LOG("GetTempFileNameA(%s, %s, %u)\n", lpPathName ? lpPathName : "(null)",
lpPrefixString ? lpPrefixString : "(null)", uUnique);
if (!lpPathName || !lpPrefixString || !lpTempFileName) {
if (!lpPathName || !lpTempFileName) {
setLastError(ERROR_INVALID_PARAMETER);
return 0;
}
Expand All @@ -1757,9 +1757,12 @@ UINT WINAPI GetTempFileNameA(LPCSTR lpPathName, LPCSTR lpPrefixString, UINT uUni
return 0;
}

// A null prefix is treated as an empty string, matching Windows/Wine.
const char *prefix = lpPrefixString ? lpPrefixString : "";

auto makeTempFileName = [&](UINT unique) {
char filename[12];
snprintf(filename, sizeof(filename), "%.3s%04X.TMP", lpPrefixString, unique & 0xFFFF);
snprintf(filename, sizeof(filename), "%.3s%04X.TMP", prefix, unique & 0xFFFF);

std::string path = lpPathName;
if (!path.empty() && path.back() != '\\' && path.back() != '/') {
Expand Down Expand Up @@ -1810,7 +1813,27 @@ UINT WINAPI GetTempFileNameA(LPCSTR lpPathName, LPCSTR lpPrefixString, UINT uUni
lpTempFileName[MAX_PATH - 1] = '\0';
DEBUG_LOG(" -> %s\n", lpTempFileName);
}
return uUnique;
return uUnique & 0xFFFF;
}

UINT WINAPI GetTempFileNameW(LPCWSTR lpPathName, LPCWSTR lpPrefixString, UINT uUnique, LPWSTR lpTempFileName) {
HOST_CONTEXT_GUARD();
DEBUG_LOG("GetTempFileNameW -> ");
if (!lpPathName || !lpTempFileName) {
setLastError(ERROR_INVALID_PARAMETER);
return 0;
}
std::string pathName = wideStringToString(lpPathName);
// A null prefix is treated as an empty string, matching Windows/Wine.
std::string prefixString = lpPrefixString ? wideStringToString(lpPrefixString) : std::string();
char tempFileName[MAX_PATH];
UINT result = GetTempFileNameA(pathName.c_str(), prefixString.c_str(), uUnique, tempFileName);
if (result == 0) {
return 0;
}
auto wide = stringToWideString(tempFileName);
wstrncpy(lpTempFileName, wide.data(), wstrlen(wide.data()) + 1);
return result;
}

DWORD WINAPI GetTempPathA(DWORD nBufferLength, LPSTR lpBuffer) {
Expand Down
1 change: 1 addition & 0 deletions dll/kernel32/fileapi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,7 @@ DWORD WINAPI GetFullPathNameW(LPCWSTR lpFileName, DWORD nBufferLength, LPWSTR lp
DWORD WINAPI GetShortPathNameA(LPCSTR lpszLongPath, LPSTR lpszShortPath, DWORD cchBuffer);
DWORD WINAPI GetShortPathNameW(LPCWSTR lpszLongPath, LPWSTR lpszShortPath, DWORD cchBuffer);
UINT WINAPI GetTempFileNameA(LPCSTR lpPathName, LPCSTR lpPrefixString, UINT uUnique, LPSTR lpTempFileName);
UINT WINAPI GetTempFileNameW(LPCWSTR lpPathName, LPCWSTR lpPrefixString, UINT uUnique, LPWSTR lpTempFileName);
DWORD WINAPI GetTempPathA(DWORD nBufferLength, LPSTR lpBuffer);
HANDLE WINAPI FindFirstFileA(LPCSTR lpFileName, LPWIN32_FIND_DATAA lpFindFileData);
HANDLE WINAPI FindFirstFileW(LPCWSTR lpFileName, LPWIN32_FIND_DATAW lpFindFileData);
Expand Down
78 changes: 76 additions & 2 deletions test/test_gettempfilename.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,22 +2,28 @@

#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include <windows.h>

static const char *basename_of(const char *path) {
const char *slash = strrchr(path, '\\');
return slash ? slash + 1 : path;
}

static const WCHAR *basename_of_w(const WCHAR *path) {
const WCHAR *slash = wcsrchr(path, L'\\');
return slash ? slash + 1 : path;
}

static void expect_fixed_unique_name(const char *temp_path) {
char temp_file[MAX_PATH];

UINT result = GetTempFileNameA(temp_path, "wboX", 0x12345, temp_file);
TEST_CHECK_EQ(0x12345, result);
TEST_CHECK_EQ(0x2345, result);
DeleteFileA(temp_file);

result = GetTempFileNameA(temp_path, "wboX", 0x12345, temp_file);
TEST_CHECK_EQ(0x12345, result);
TEST_CHECK_EQ(0x2345, result);
TEST_CHECK_STR_EQ("wbo2345.TMP", basename_of(temp_file));
TEST_CHECK_EQ(INVALID_FILE_ATTRIBUTES, GetFileAttributesA(temp_file));
}
Expand All @@ -39,13 +45,81 @@ static void expect_created_file_reopens_like_link(const char *temp_path) {
TEST_CHECK(CloseHandle(handle));
}

static void expect_null_prefix_is_empty(const char *temp_path) {
char temp_file[MAX_PATH];

UINT result = GetTempFileNameA(temp_path, NULL, 0x12345, temp_file);
TEST_CHECK_EQ(0x2345, result);
TEST_CHECK_STR_EQ("2345.TMP", basename_of(temp_file));
}

static void expect_fixed_unique_name_w(const WCHAR *temp_path) {
WCHAR temp_file[MAX_PATH];

UINT result = GetTempFileNameW(temp_path, L"wboX", 0x12345, temp_file);
TEST_CHECK_EQ(0x2345, result);
DeleteFileW(temp_file);

result = GetTempFileNameW(temp_path, L"wboX", 0x12345, temp_file);
TEST_CHECK_EQ(0x2345, result);
TEST_CHECK(wcscmp(L"wbo2345.TMP", basename_of_w(temp_file)) == 0);
TEST_CHECK_EQ(INVALID_FILE_ATTRIBUTES, GetFileAttributesW(temp_file));
}

static void expect_created_file_reopens_like_link_w(const WCHAR *temp_path) {
WCHAR temp_file[MAX_PATH];

UINT result = GetTempFileNameW(temp_path, L"GDI32", 0, temp_file);
TEST_CHECK(result != 0);
TEST_CHECK_EQ(11, wcslen(basename_of_w(temp_file)));
TEST_CHECK_EQ(0, wcsncmp(L"GDI", basename_of_w(temp_file), 3));
TEST_CHECK(wcscmp(L".TMP", basename_of_w(temp_file) + 7) == 0);
TEST_CHECK(GetFileAttributesW(temp_file) != INVALID_FILE_ATTRIBUTES);

HANDLE handle = CreateFileW(temp_file, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE, NULL);
TEST_CHECK_MSG(handle != INVALID_HANDLE_VALUE, "CreateFileW(temp, OPEN_EXISTING|DELETE_ON_CLOSE) failed: %lu",
GetLastError());
TEST_CHECK(CloseHandle(handle));
}

static void expect_null_prefix_is_empty_w(const WCHAR *temp_path) {
WCHAR temp_file[MAX_PATH];

UINT result = GetTempFileNameW(temp_path, NULL, 0x12345, temp_file);
TEST_CHECK_EQ(0x2345, result);
TEST_CHECK(wcscmp(L"2345.TMP", basename_of_w(temp_file)) == 0);
}

static void expect_invalid_parameters_w(const WCHAR *temp_path) {
WCHAR temp_file[MAX_PATH];

SetLastError(0);
TEST_CHECK_EQ(0, GetTempFileNameW(NULL, L"wbo", 0, temp_file));
TEST_CHECK_EQ(ERROR_INVALID_PARAMETER, GetLastError());

SetLastError(0);
TEST_CHECK_EQ(0, GetTempFileNameW(temp_path, L"wbo", 0, NULL));
TEST_CHECK_EQ(ERROR_INVALID_PARAMETER, GetLastError());
}

int main(void) {
char temp_path[MAX_PATH];
DWORD len = GetTempPathA(sizeof(temp_path), temp_path);
TEST_CHECK(len > 0 && len < sizeof(temp_path));

expect_fixed_unique_name(temp_path);
expect_created_file_reopens_like_link(temp_path);
expect_null_prefix_is_empty(temp_path);

WCHAR temp_path_w[MAX_PATH];
int wlen = MultiByteToWideChar(CP_ACP, 0, temp_path, -1, temp_path_w, MAX_PATH);
TEST_CHECK(wlen > 0);

expect_fixed_unique_name_w(temp_path_w);
expect_created_file_reopens_like_link_w(temp_path_w);
expect_null_prefix_is_empty_w(temp_path_w);
expect_invalid_parameters_w(temp_path_w);

return 0;
}
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