shlwapi: Make UrlCanonicalizeW working with long urls (>INTERNET_MAX_URL_LENGTH).

dlls/shlwapi/url.c

@@ -287,11 +287,12 @@ HRESULT WINAPI UrlCanonicalizeW(LPCWSTR pszUrl, LPWSTR pszCanonicalized,
     static const WCHAR wszFile[] = {'f','i','l','e',':'};
     static const WCHAR wszRes[] = {'r','e','s',':'};
     static const WCHAR wszLocalhost[] = {'l','o','c','a','l','h','o','s','t'};
+    static const WCHAR wszFilePrefix[] = {'f','i','l','e',':','/','/','/'};
 
     TRACE("(%s, %p, %p, 0x%08x) *pcchCanonicalized: %d\n", debugstr_w(pszUrl), pszCanonicalized,
         pcchCanonicalized, dwFlags, pcchCanonicalized ? *pcchCanonicalized : -1);
 
-    if(!pszUrl || !pszCanonicalized || !pcchCanonicalized)
+    if(!pszUrl || !pszCanonicalized || !pcchCanonicalized || !*pcchCanonicalized)
 	return E_INVALIDARG;
 
     if(!*pszUrl) {
@@ -300,8 +301,9 @@ HRESULT WINAPI UrlCanonicalizeW(LPCWSTR pszUrl, LPWSTR pszCanonicalized,
     }
 
     nByteLen = (strlenW(pszUrl) + 1) * sizeof(WCHAR); /* length in bytes */
+    /* Allocate memory for simplified URL (before escaping) */
     lpszUrlCpy = HeapAlloc(GetProcessHeap(), 0,
-                           INTERNET_MAX_URL_LENGTH * sizeof(WCHAR));
+            nByteLen+sizeof(wszFilePrefix)+sizeof(WCHAR));
 
     if((dwFlags & URL_FILE_USE_PATHURL) && nByteLen >= sizeof(wszFile)
             && !memcmp(wszFile, pszUrl, sizeof(wszFile)))
@@ -328,8 +330,6 @@ HRESULT WINAPI UrlCanonicalizeW(LPCWSTR pszUrl, LPWSTR pszCanonicalized,
     state = 0;
 
     if(pszUrl[1] == ':') { /* Assume path */
-        static const WCHAR wszFilePrefix[] = {'f','i','l','e',':','/','/','/'};
-
         memcpy(wk2, wszFilePrefix, sizeof(wszFilePrefix));
         wk2 += sizeof(wszFilePrefix)/sizeof(WCHAR);
         if (dwFlags & URL_FILE_USE_PATHURL)
@@ -833,6 +833,8 @@ HRESULT WINAPI UrlCombineW(LPCWSTR pszBase, LPCWSTR pszRelative,
 
     if (ret == S_OK) {
 	/* Reuse mrelative as temp storage as its already allocated and not needed anymore */
+        if(*pcchCombined == 0)
+            *pcchCombined = 1;
 	ret = UrlCanonicalizeW(preliminary, mrelative, pcchCombined, (dwFlags & ~URL_FILE_USE_PATHURL));
 	if(SUCCEEDED(ret) && pszCombined) {
 	    lstrcpyW(pszCombined, mrelative);