kernel32 + user32: stub GetOEMCP / SetFileApisToOEM / CharToOem* / OemToChar*

dll/kernel32/winnls.cpp

@@ -97,6 +97,24 @@ UINT WINAPI GetACP() {
 	return 28591; // Latin1 (ISO/IEC 8859-1)
 }
 
+UINT WINAPI GetOEMCP() {
+	HOST_CONTEXT_GUARD();
+	// IBM PC US (codepage 437) is the canonical OEM codepage for NT-era
+	// tools built on English locales; matches what Wine and NT return by
+	// default when no locale override is present.
+	DEBUG_LOG("GetOEMCP() -> %u\n", 437);
+	return 437;
+}
+
+BOOL WINAPI SetFileApisToOEM() {
+	// Switches kernel32 Ansi<->Oem conversion for file-path APIs. Since
+	// our codepages are effectively 1:1 mappings for ASCII, there's
+	// nothing to configure; returning success is safe.
+	HOST_CONTEXT_GUARD();
+	DEBUG_LOG("SetFileApisToOEM() -> TRUE (no-op)\n");
+	return TRUE;
+}
+
 LANGID WINAPI GetSystemDefaultLangID() {
 	HOST_CONTEXT_GUARD();
 	DEBUG_LOG("STUB: GetSystemDefaultLangID()\n");

dll/kernel32/winnls.h

@@ -17,6 +17,8 @@ typedef BOOL(_CC_STDCALL *LOCALE_ENUMPROCA)(LPSTR);
 namespace kernel32 {
 
 UINT WINAPI GetACP();
+UINT WINAPI GetOEMCP();
+BOOL WINAPI SetFileApisToOEM();
 LANGID WINAPI GetSystemDefaultLangID();
 LANGID WINAPI GetUserDefaultUILanguage();
 int WINAPI GetUserDefaultLocaleName(LPWSTR lpLocaleName, int cchLocaleName);

dll/user32.cpp

@@ -175,6 +175,48 @@ HWND WINAPI GetActiveWindow() {
 	return NO_HANDLE;
 }
 
+/*
+ * CharToOem / OemToChar conversion between the "ANSI" and "OEM" codepages.
+ * For the codepages wibo exposes (GetACP=1252 Latin1 / 28591, GetOEMCP=437)
+ * the ASCII range 0x00-0x7F is identity in both directions; the high-half
+ * differs but NT-era build tools (MC, RC) only feed these APIs argv
+ * strings and filenames, which in practice are ASCII. We implement
+ * identity mapping: correct for ASCII, safe fallback for high-bytes, and
+ * sufficient for our build pipeline.
+ */
+static BOOL charToOemA_impl(LPCSTR src, LPSTR dst, DWORD length, BOOL counted) {
+	if (!src || !dst) return FALSE;
+	if (counted) {
+		for (DWORD i = 0; i < length; i++) dst[i] = src[i];
+	} else {
+		while (*src) *dst++ = *src++;
+		*dst = 0;
+	}
+	return TRUE;
+}
+
+BOOL WINAPI CharToOemA(LPCSTR lpszSrc, LPSTR lpszDst) {
+	DEBUG_LOG("CharToOemA(%p, %p) (identity)\n", lpszSrc, lpszDst);
+	return charToOemA_impl(lpszSrc, lpszDst, 0, FALSE);
+}
+
+BOOL WINAPI CharToOemBuffA(LPCSTR lpszSrc, LPSTR lpszDst, DWORD cchDstLength) {
+	DEBUG_LOG("CharToOemBuffA(%p, %p, %lu)\n", lpszSrc, lpszDst,
+			  static_cast<unsigned long>(cchDstLength));
+	return charToOemA_impl(lpszSrc, lpszDst, cchDstLength, TRUE);
+}
+
+BOOL WINAPI OemToCharA(LPCSTR lpszSrc, LPSTR lpszDst) {
+	DEBUG_LOG("OemToCharA(%p, %p) (identity)\n", lpszSrc, lpszDst);
+	return charToOemA_impl(lpszSrc, lpszDst, 0, FALSE);
+}
+
+BOOL WINAPI OemToCharBuffA(LPCSTR lpszSrc, LPSTR lpszDst, DWORD cchDstLength) {
+	DEBUG_LOG("OemToCharBuffA(%p, %p, %lu)\n", lpszSrc, lpszDst,
+			  static_cast<unsigned long>(cchDstLength));
+	return charToOemA_impl(lpszSrc, lpszDst, cchDstLength, TRUE);
+}
+
 } // namespace user32
 
 #include "user32_trampolines.h"

dll/user32.h

@@ -11,5 +11,9 @@ HKL WINAPI GetKeyboardLayout(DWORD idThread);
 HWINSTA WINAPI GetProcessWindowStation();
 BOOL WINAPI GetUserObjectInformationA(HANDLE hObj, int nIndex, PVOID pvInfo, DWORD nLength, LPDWORD lpnLengthNeeded);
 HWND WINAPI GetActiveWindow();
+BOOL WINAPI CharToOemA(LPCSTR lpszSrc, LPSTR lpszDst);
+BOOL WINAPI CharToOemBuffA(LPCSTR lpszSrc, LPSTR lpszDst, DWORD cchDstLength);
+BOOL WINAPI OemToCharA(LPCSTR lpszSrc, LPSTR lpszDst);
+BOOL WINAPI OemToCharBuffA(LPCSTR lpszSrc, LPSTR lpszDst, DWORD cchDstLength);
 
 } // namespace user32