[SHLWAPI][SHLWAPI_APITEST][SDK] Support NextPathA/W (#9039)

Implementing missing features...
JIRA issue: CORE-19278
- Implement NextPathA and
  NextPathW functions.
- Modify shlwapi.spec.
- Add prototypes into
  <shlwapi_undoc.h>.
- Add NextPath testcase.

dll/win32/shlwapi/shlwapi.spec

@@ -446,8 +446,8 @@
 446 stdcall -noname PathFileExistsAndAttributesW(wstr ptr)
 447 stdcall -noname FixSlashesAndColonA(str)
 448 stdcall -noname FixSlashesAndColonW(wstr)
-449 stub -noname NextPathA
-450 stub -noname NextPathW
+449 stdcall -noname NextPathA(str ptr long)
+450 stdcall -noname NextPathW(wstr ptr long)
 451 stdcall -noname CharUpperNoDBCSA(str)
 452 stdcall -noname CharUpperNoDBCSW(wstr)
 453 stdcall -noname CharLowerNoDBCSA(str)

dll/win32/shlwapi/utils.cpp

@@ -878,3 +878,82 @@ SHDialogBox(
     SHDIALOG data = { fn, pThis };
     return DialogBoxParamA(hInstance, lpTemplateName, hWndParent, SHDialogProc, (LPARAM)&data);
 }
+
+/*************************************************************************
+ * NextPathA [SHLWAPI.449]
+ *
+ * See NextPathW.
+ */
+EXTERN_C PSTR WINAPI
+NextPathA(
+    _In_ PCSTR pszStart,
+    _Out_writes_(cchDest) PSTR pszDest,
+    _In_ UINT cchDest)
+{
+    if (!pszStart)
+        return NULL;
+
+    PCSTR pchStart = pszStart;
+    while (*pchStart == ';')
+        ++pchStart;
+
+    if (!*pchStart)
+        return NULL;
+
+    PSTR pchEnd = StrChrA(pchStart, ';');
+    if (!pchEnd)
+        pchEnd = (PSTR)(pchStart + lstrlenA(pchStart));
+
+    const UINT cchSegment = (UINT)(pchEnd - pchStart);
+    const UINT cchToCopy = min(cchSegment + 1, cchDest);
+    lstrcpynA(pszDest, pchStart, cchToCopy);
+    pszDest[cchSegment] = ANSI_NULL;
+
+    PathRemoveBlanksA(pszDest);
+    if (!*pszDest)
+        return NULL;
+
+    return (*pchEnd == ';') ? (pchEnd + 1) : pchEnd;
+}
+
+/*************************************************************************
+ * NextPathW [SHLWAPI.450]
+ *
+ * Extracts the next path from a semicolon-separated path string (Unicode version)
+ *
+ * @param pszStart Parsing start position (semicolon-separated path string)
+ * @param pszDest Buffer to store the extracted path
+ * @param cchDest Buffer size (number of characters)
+ * @return Pointer to the beginning of the next path. NULL if there are no more paths.
+ */
+EXTERN_C PWSTR WINAPI
+NextPathW(
+    _In_ PCWSTR pszStart,
+    _Out_writes_(cchDest) PWSTR pszDest,
+    _In_ UINT cchDest)
+{
+    if (!pszStart)
+        return NULL;
+
+    PCWSTR pchStart = pszStart;
+    while (*pchStart == L';')
+        ++pchStart;
+
+    if (!*pchStart)
+        return NULL;
+
+    PWSTR pchEnd = StrChrW(pchStart, L';');
+    if (!pchEnd)
+        pchEnd = (PWSTR)(pchStart + lstrlenW(pchStart));
+
+    const UINT cchSegment = (UINT)(pchEnd - pchStart);
+    const UINT cchToCopy = min(cchSegment + 1, cchDest);
+    lstrcpynW(pszDest, pchStart, cchToCopy);
+    pszDest[cchSegment] = UNICODE_NULL;
+
+    PathRemoveBlanksW(pszDest);
+    if (!*pszDest)
+        return NULL;
+
+    return (*pchEnd == L';') ? (pchEnd + 1) : pchEnd;
+}

modules/rostests/apitests/shlwapi/CMakeLists.txt

@@ -10,6 +10,7 @@ list(APPEND SOURCE
     IShellFolderHelpers.cpp
     IsQSForward.cpp
     IStreamPidl.cpp
+    NextPath.c
     PathFileExistsDefExtAndAttributesW.c
     PathFindOnPath.c
     PathIsUNC.c

modules/rostests/apitests/shlwapi/NextPath.c

@@ -0,0 +1,158 @@
+/*
+ * PROJECT:     ReactOS api tests
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Tests for NextPathA/W
+ * COPYRIGHT:   Copyright 2026 Katayama Hirofumi MZ <[email protected]>
+ */
+
+#include <apitest.h>
+#include <shlwapi.h>
+
+typedef PSTR  (WINAPI *FN_NextPathA)(PCSTR, PSTR, UINT);
+typedef PWSTR (WINAPI *FN_NextPathW)(PCWSTR, PWSTR, UINT);
+
+static FN_NextPathA s_pNextPathA = NULL;
+static FN_NextPathW s_pNextPathW = NULL;
+
+static void TEST_NextPathA(void)
+{
+    PSTR pch;
+    CHAR sz[MAX_PATH];
+
+    /* NULL pszStart returns NULL */
+    pch = s_pNextPathA(NULL, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Basic semicolon-separated paths */
+    pch = s_pNextPathA("C:\\TEST1;C:\\TEST2;C:\\TEST3", sz, _countof(sz));
+    ok_str(sz, "C:\\TEST1");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok_str(sz, "C:\\TEST2");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok_str(sz, "C:\\TEST3");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Whitespace-only segment */
+    pch = s_pNextPathA("C:\\TEST1;   ;C:\\TEST3", sz, _countof(sz));
+    ok_str(sz, "C:\\TEST1");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Empty string: no paths at all */
+    pch = s_pNextPathA("", sz, _countof(sz));
+    ok(pch == NULL, "empty string: pch was %p\n", pch);
+
+    /* Leading semicolons are skipped */
+    pch = s_pNextPathA(";;;C:\\TEST1", sz, _countof(sz));
+    ok_str(sz, "C:\\TEST1");
+    ok(pch != NULL, "leading semicolons: pch should not be NULL\n");
+
+    /* Trailing semicolon */
+    pch = s_pNextPathA("C:\\TEST1;", sz, _countof(sz));
+    ok_str(sz, "C:\\TEST1");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok(pch == NULL, "trailing semicolon: pch was %p\n", pch);
+
+    /* Only semicolons */
+    pch = s_pNextPathA(";;;", sz, _countof(sz));
+    ok(pch == NULL, "only semicolons: pch was %p\n", pch);
+
+    /* Path with surrounding spaces */
+    pch = s_pNextPathA("  C:\\TEST1  ;C:\\TEST2", sz, _countof(sz));
+    ok_str(sz, "C:\\TEST1");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok_str(sz, "C:\\TEST2");
+
+    /* Single path, no semicolon */
+    pch = s_pNextPathA("C:\\SINGLE", sz, _countof(sz));
+    ok_str(sz, "C:\\SINGLE");
+    pch = s_pNextPathA(pch, sz, _countof(sz));
+    ok(pch == NULL, "single path: pch was %p\n", pch);
+
+    /* cchDest = 0 */
+    sz[0] = '*';
+    sz[1] = ANSI_NULL;
+    pch = s_pNextPathA("C:\\TEST1;C:\\TEST2;C:\\TEST3", sz, 0);
+    ok_str(pch, "C:\\TEST2;C:\\TEST3");
+    ok_str(sz, "*");
+}
+
+static void TEST_NextPathW(void)
+{
+    PWSTR pch;
+    WCHAR sz[MAX_PATH];
+
+    /* NULL pszStart returns NULL */
+    pch = s_pNextPathW(NULL, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Basic semicolon-separated paths */
+    pch = s_pNextPathW(L"C:\\TEST1;C:\\TEST2;C:\\TEST3", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST1");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST2");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST3");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Whitespace-only segment */
+    pch = s_pNextPathW(L"C:\\TEST1;   ;C:\\TEST3", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST1");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok(pch == NULL, "pch was %p\n", pch);
+
+    /* Empty string */
+    pch = s_pNextPathW(L"", sz, _countof(sz));
+    ok(pch == NULL, "empty string: pch was %p\n", pch);
+
+    /* Leading semicolons are skipped */
+    pch = s_pNextPathW(L";;;C:\\TEST1", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST1");
+    ok(pch != NULL, "leading semicolons: pch should not be NULL\n");
+
+    /* Trailing semicolon */
+    pch = s_pNextPathW(L"C:\\TEST1;", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST1");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok(pch == NULL, "trailing semicolon: pch was %p\n", pch);
+
+    /* Only semicolons */
+    pch = s_pNextPathW(L";;;", sz, _countof(sz));
+    ok(pch == NULL, "only semicolons: pch was %p\n", pch);
+
+    /* Path with surrounding spaces */
+    pch = s_pNextPathW(L"  C:\\TEST1  ;C:\\TEST2", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST1");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok_wstr(sz, L"C:\\TEST2");
+
+    /* Single path, no semicolon */
+    pch = s_pNextPathW(L"C:\\SINGLE", sz, _countof(sz));
+    ok_wstr(sz, L"C:\\SINGLE");
+    pch = s_pNextPathW(pch, sz, _countof(sz));
+    ok(pch == NULL, "single path: pch was %p\n", pch);
+
+    /* cchDest = 0 */
+    sz[0] = L'*';
+    sz[1] = UNICODE_NULL;
+    pch = s_pNextPathW(L"C:\\TEST1;C:\\TEST2;C:\\TEST3", sz, 0);
+    ok_wstr(pch, L"C:\\TEST2;C:\\TEST3");
+    ok_wstr(sz, L"*");
+}
+
+START_TEST(NextPath)
+{
+    HINSTANCE hSHLWAPI = GetModuleHandleA("shlwapi");
+    s_pNextPathA = (FN_NextPathA)GetProcAddress(hSHLWAPI, MAKEINTRESOURCEA(449));
+    s_pNextPathW = (FN_NextPathW)GetProcAddress(hSHLWAPI, MAKEINTRESOURCEA(450));
+    if (!s_pNextPathA || !s_pNextPathW)
+    {
+        skip("NextPath not found\n");
+        return;
+    }
+
+    TEST_NextPathA();
+    TEST_NextPathW();
+}

modules/rostests/apitests/shlwapi/testlist.c

@@ -8,6 +8,7 @@ extern void func_PathFindOnPath(void);
 extern void func_IShellFolderHelpers(void);
 extern void func_IsQSForward(void);
 extern void func_IStreamPidl(void);
+extern void func_NextPath(void);
 extern void func_PathIsUNC(void);
 extern void func_PathIsUNCServer(void);
 extern void func_PathIsUNCServerShare(void);
@@ -33,6 +34,7 @@ const struct test winetest_testlist[] =
     { "IShellFolderHelpers", func_IShellFolderHelpers },
     { "IsQSForward", func_IsQSForward },
     { "IStreamPidl", func_IStreamPidl },
+    { "NextPath", func_NextPath },
     { "PathIsUNC", func_PathIsUNC },
     { "PathIsUNCServer", func_PathIsUNCServer },
     { "PathIsUNCServerShare", func_PathIsUNCServerShare },

sdk/include/reactos/shlwapi_undoc.h

@@ -60,10 +60,25 @@ SHRestrictionLookup(
 
 BOOL WINAPI SHAboutInfoA(LPSTR lpszDest, DWORD dwDestLen);
 BOOL WINAPI SHAboutInfoW(LPWSTR lpszDest, DWORD dwDestLen);
+
+PSTR WINAPI
+NextPathA(
+    _In_ PCSTR pszStart,
+    _Out_writes_(cchDest) PSTR pszDest,
+    _In_ UINT cchDest);
+
+PWSTR WINAPI
+NextPathW(
+    _In_ PCWSTR pszStart,
+    _Out_writes_(cchDest) PWSTR pszDest,
+    _In_ UINT cchDest);
+
 #ifdef UNICODE
 #define SHAboutInfo SHAboutInfoW
+#define NextPath NextPathW
 #else
 #define SHAboutInfo SHAboutInfoA
+#define NextPath NextPathA
 #endif
 
 HRESULT WINAPI CLSIDFromStringWrap(_In_ LPCWSTR idstr, _Out_ CLSID *id);