Make sure GetTempFileName never returns 0 on success.

files/file.c

@@ -1064,17 +1064,44 @@ BOOL WINAPI GetFileTime( HANDLE hFile, FILETIME *lpCreationTime,
 
 
 /***********************************************************************
- *           FILE_GetTempFileName : utility for GetTempFileName
+ *           GetTempFileNameA   (KERNEL32.@)
+ */
+UINT WINAPI GetTempFileNameA( LPCSTR path, LPCSTR prefix, UINT unique,
+                                  LPSTR buffer)
+{
+    UNICODE_STRING pathW, prefixW;
+    WCHAR bufferW[MAX_PATH];
+    UINT ret;
+
+    if ( !path || !prefix || !buffer )
+    {
+        SetLastError( ERROR_INVALID_PARAMETER );
+        return 0;
+    }
+
+    RtlCreateUnicodeStringFromAsciiz(&pathW, path);
+    RtlCreateUnicodeStringFromAsciiz(&prefixW, prefix);
+
+    ret = GetTempFileNameW(pathW.Buffer, prefixW.Buffer, unique, bufferW);
+    if (ret)
+        WideCharToMultiByte(CP_ACP, 0, bufferW, -1, buffer, MAX_PATH, NULL, NULL);
+
+    RtlFreeUnicodeString(&pathW);
+    RtlFreeUnicodeString(&prefixW);
+    return ret;
+}
+
+/***********************************************************************
+ *           GetTempFileNameW   (KERNEL32.@)
  */
-static UINT FILE_GetTempFileName( LPCWSTR path, LPCWSTR prefix, UINT unique,
+UINT WINAPI GetTempFileNameW( LPCWSTR path, LPCWSTR prefix, UINT unique,
                                   LPWSTR buffer )
 {
-    static UINT unique_temp;
+    static const WCHAR formatW[] = {'%','0','4','x','.','t','m','p',0};
+
     DOS_FULL_NAME full_name;
     int i;
     LPWSTR p;
-    UINT num;
-    char buf[20];
 
     if ( !path || !prefix || !buffer )
     {
@@ -1082,29 +1109,31 @@ static UINT FILE_GetTempFileName( LPCWSTR path, LPCWSTR prefix, UINT unique,
         return 0;
     }
 
-    if (!unique_temp) unique_temp = time(NULL) & 0xffff;
-    num = unique ? (unique & 0xffff) : (unique_temp++ & 0xffff);
-
     strcpyW( buffer, path );
     p = buffer + strlenW(buffer);
 
     /* add a \, if there isn't one and path is more than just the drive letter ... */
     if ( !((strlenW(buffer) == 2) && (buffer[1] == ':'))
-	&& ((p == buffer) || (p[-1] != '\\'))) *p++ = '\\';
+       && ((p == buffer) || (p[-1] != '\\'))) *p++ = '\\';
 
     for (i = 3; (i > 0) && (*prefix); i--) *p++ = *prefix++;
 
-    sprintf( buf, "%04x.tmp", num );
-    MultiByteToWideChar(CP_ACP, 0, buf, -1, p, 20);
+    unique &= 0xffff;
 
-    /* Now try to create it */
-
-    if (!unique)
+    if (unique) sprintfW( p, formatW, unique );
+    else
     {
+        /* get a "random" unique number and try to create the file */
+        HANDLE handle;
+        UINT num = GetTickCount() & 0xffff;
+
+        if (!num) num = 1;
+        unique = num;
         do
         {
-            HANDLE handle = CreateFileW( buffer, GENERIC_WRITE, 0, NULL,
-                                         CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0 );
+            sprintfW( p, formatW, unique );
+            handle = CreateFileW( buffer, GENERIC_WRITE, 0, NULL,
+                                  CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0 );
             if (handle != INVALID_HANDLE_VALUE)
             {  /* We created it */
                 TRACE("created %s\n", debugstr_w(buffer) );
@@ -1114,10 +1143,8 @@ static UINT FILE_GetTempFileName( LPCWSTR path, LPCWSTR prefix, UINT unique,
             if (GetLastError() != ERROR_FILE_EXISTS &&
                 GetLastError() != ERROR_SHARING_VIOLATION)
                 break;  /* No need to go on */
-            num++;
-            sprintf( buf, "%04x.tmp", num );
-            MultiByteToWideChar(CP_ACP, 0, buf, -1, p, 20);
-        } while (num != (unique & 0xffff));
+            if (!(++unique & 0xffff)) unique = 1;
+        } while (unique != num);
     }
 
     /* Get the full path name */
@@ -1132,45 +1159,7 @@ static UINT FILE_GetTempFileName( LPCWSTR path, LPCWSTR prefix, UINT unique,
                   debugstr_w(buffer) );
     }
     TRACE("returning %s\n", debugstr_w(buffer) );
-    return unique ? unique : num;
-}
-
-
-/***********************************************************************
- *           GetTempFileNameA   (KERNEL32.@)
- */
-UINT WINAPI GetTempFileNameA( LPCSTR path, LPCSTR prefix, UINT unique,
-                                  LPSTR buffer)
-{
-    UNICODE_STRING pathW, prefixW;
-    WCHAR bufferW[MAX_PATH];
-    UINT ret;
-
-    if ( !path || !prefix || !buffer )
-    {
-        SetLastError( ERROR_INVALID_PARAMETER );
-        return 0;
-    }
-
-    RtlCreateUnicodeStringFromAsciiz(&pathW, path);
-    RtlCreateUnicodeStringFromAsciiz(&prefixW, prefix);
-
-    ret = GetTempFileNameW(pathW.Buffer, prefixW.Buffer, unique, bufferW);
-    if (ret)
-        WideCharToMultiByte(CP_ACP, 0, bufferW, -1, buffer, MAX_PATH, NULL, NULL);
-
-    RtlFreeUnicodeString(&pathW);
-    RtlFreeUnicodeString(&prefixW);
-    return ret;
-}
-
-/***********************************************************************
- *           GetTempFileNameW   (KERNEL32.@)
- */
-UINT WINAPI GetTempFileNameW( LPCWSTR path, LPCWSTR prefix, UINT unique,
-                                  LPWSTR buffer )
-{
-    return FILE_GetTempFileName( path, prefix, unique, buffer );
+    return unique;
 }