Util (Windows): fix possible errors in Unicode.c

Author: CarterLi

src/util/windows/unicode.c

@@ -11,22 +11,12 @@ void ffStrbufSetNWS(FFstrbuf* result, uint32_t length, const wchar_t* source)
     }
 
     int size_needed = WideCharToMultiByte(CP_UTF8, 0, source, (int)length, NULL, 0, NULL, NULL);
-    ffStrbufEnsureFree(result, (uint32_t)size_needed);
-    WideCharToMultiByte(CP_UTF8, 0, source, (int)length, result->chars, size_needed, NULL, NULL);
-    result->length = (uint32_t)size_needed;
-    result->chars[size_needed] = '\0';
-}
-
-void ffStrbufInitNWS(FFstrbuf* result, uint32_t length, const wchar_t* source)
-{
-    if(!length)
+    if (size_needed < 0)
     {
-        ffStrbufInit(result);
+        ffStrbufSetF(result, "WCTMB failed: %u", (unsigned) GetLastError());
         return;
     }
-
-    int size_needed = WideCharToMultiByte(CP_UTF8, 0, source, (int)length, NULL, 0, NULL, NULL);
-    ffStrbufInitA(result, (uint32_t)size_needed + 1);
+    ffStrbufEnsureFixedLengthFree(result, (uint32_t)size_needed);
     WideCharToMultiByte(CP_UTF8, 0, source, (int)length, result->chars, size_needed, NULL, NULL);
     result->length = (uint32_t)size_needed;
     result->chars[size_needed] = '\0';

src/util/windows/unicode.h

@@ -11,7 +11,11 @@ static inline void ffStrbufSetWS(FFstrbuf* result, const wchar_t* source)
     return ffStrbufSetNWS(result, (uint32_t)wcslen(source), source);
 }
 
-void ffStrbufInitNWS(FFstrbuf* result, uint32_t length, const wchar_t* source);
+static inline void ffStrbufInitNWS(FFstrbuf* result, uint32_t length, const wchar_t* source)
+{
+    ffStrbufInit(result);
+    return ffStrbufSetNWS(result, length, source);
+}
 
 static inline void ffStrbufInitWS(FFstrbuf* result, const wchar_t* source)
 {