shell32: Fixes for bugs found by valgrind on shell32 tests harness.

- read strings from left to right (PathGetDriveNumberW)
- don't access buffers before they are filled (SHGetPathFromIDListW)
- fill buffers & variables on all paths (SHELL_FindExecutable)
- handle error condition (unix_fs)
- don't shoot in the blind for AW APIs (tests/shelllink.c)

dlls/shell32/pidl.c

@@ -1259,7 +1259,7 @@ BOOL WINAPI SHGetPathFromIDListW(LPCITEMIDLIST pidl, LPWSTR pszPath)
     DWORD dwAttributes;
     STRRET strret;
 
-    TRACE_(shell)("(pidl=%p,%p)\n", pidl, debugstr_w(pszPath));
+    TRACE_(shell)("(pidl=%p,%p)\n", pidl, pszPath);
     pdump(pidl);
 
     if (!pidl)

dlls/shell32/shfldr_unixfs.c

@@ -701,6 +701,7 @@ static BOOL UNIXFS_path_to_pidl(UnixFolder *pUnixFolder, const WCHAR *path, LPIT
             
         if (!pNextPathElement) {
             SHFree(*ppidl);
+            *ppidl = NULL;
             return FALSE;
         }
         pidl = ILGetNext(pidl);
@@ -1753,7 +1754,7 @@ static HRESULT WINAPI UnixFolder_ISFHelper_AddFolder(ISFHelper* iface, HWND hwnd
                 ILFree(pidlRelative);
             SHChangeNotify(SHCNE_MKDIR, SHCNF_IDLIST, pidlAbsolute, NULL);
             ILFree(pidlAbsolute);
-        }
+        } else return E_FAIL;
         return S_OK;
     }
 }

dlls/shell32/shlexec.c

@@ -597,6 +597,11 @@ UINT SHELL_FindExecutable(LPCWSTR lpPath, LPCWSTR lpFile, LPCWSTR lpOperation,
             filetype[filetypelen] = '\0';
             TRACE("File type: %s\n", debugstr_w(filetype));
         }
+        else
+        {
+            *filetype = '\0';
+            filetypelen = 0;
+        }
     }
 
     if (*filetype)

dlls/shell32/tests/shelllink.c

@@ -43,23 +43,24 @@ static const WCHAR notafile[]= { 'C',':','\\','n','o','n','e','x','i','s','t','e
  * SHSimpleIDListFromPathA does not work on NT4. But if we call both we
  * get what we want on all platforms.
  */
-static LPITEMIDLIST (WINAPI *pSHSimpleIDListFromPathA)(LPCSTR)=NULL;
+static LPITEMIDLIST (WINAPI *pSHSimpleIDListFromPathAW)(LPCVOID);
 
 static LPITEMIDLIST path_to_pidl(const char* path)
 {
     LPITEMIDLIST pidl;
 
-    if (!pSHSimpleIDListFromPathA)
+    if (!pSHSimpleIDListFromPathAW)
     {
         HMODULE hdll=LoadLibraryA("shell32.dll");
-        pSHSimpleIDListFromPathA=(void*)GetProcAddress(hdll, (char*)162);
-        if (!pSHSimpleIDListFromPathA)
-            trace("SHSimpleIDListFromPathA not found in shell32.dll\n");
+        pSHSimpleIDListFromPathAW=(void*)GetProcAddress(hdll, (char*)162);
+        if (!pSHSimpleIDListFromPathAW)
+            trace("SHSimpleIDListFromPathAW not found in shell32.dll\n");
     }
 
     pidl=NULL;
-    if (pSHSimpleIDListFromPathA)
-        pidl=pSHSimpleIDListFromPathA(path);
+    /* pSHSimpleIDListFromPathAW maps to A on non NT platforms */
+    if (pSHSimpleIDListFromPathAW && (GetVersion() & 0x80000000))
+        pidl=pSHSimpleIDListFromPathAW(path);
 
     if (!pidl)
     {

dlls/shlwapi/path.c

@@ -506,9 +506,12 @@ int WINAPI PathGetDriveNumberW(LPCWSTR lpszPath)
 {
   TRACE ("(%s)\n",debugstr_w(lpszPath));
 
-  if (lpszPath && lpszPath[1] == ':' &&
-      tolowerW(*lpszPath) >= 'a' && tolowerW(*lpszPath) <= 'z')
-    return tolowerW(*lpszPath) - 'a';
+  if (lpszPath)
+  {
+      WCHAR tl = tolowerW(lpszPath[0]);
+      if (tl >= 'a' && tl <= 'z' && lpszPath[1] == ':')
+          return tl - 'a';
+  }
   return -1;
 }