Use of uninitialized variable in combine_uri()

[Gerald Pfeifer]

Hi Thomas,

the following change of yours 

  commit bced2e21dbc548ef9d41e3ff11384d7ad964c929
  Author: Thomas Mullaly thomas.mull...@gmail.com
  Date:   Sat Oct 9 11:02:17 2010 -0400

urlmon: Implemented base case for CoInternetCombineIUri.

introduces a new warning, use of uninitialized variable in the line
marked HERE below.

  +static HRESULT combine_uri(Uri *base, Uri *relative, DWORD flags, IUri 
**result
  +Uri *ret;
  +HRESULT hr;
  +parse_data data;
  +
  +/* Base case is when the relative Uri has a scheme name,
  + * if it does, then 'result' will contain the same data
  + * as the relative Uri.
  + */
  +if(relative-scheme_start  -1) {
  +DWORD create_flags = 0;
  +
  +memset(data, 0, sizeof(parse_data));
  +
  +data.uri = SysAllocString(relative-raw_uri);
  +if(!data.uri) {
  +IUri_Release(URI(ret)); == HERE
  +*result = NULL;
  +return E_OUTOFMEMORY;
  +}

From all I can tell this is a legitimate warning, that is, the code
really invokes undefined behavior.  Would you mind having a look?

Gerald

Re: Use of uninitialized variable in combine_uri()

[Thomas Mullaly]

Hi Gerald,

On Tue, Nov 2, 2010 at 6:51 PM, Gerald Pfeifer ger...@pfeifer.com wrote:
 Hi Thomas,

 the following change of yours

  commit bced2e21dbc548ef9d41e3ff11384d7ad964c929
  Author: Thomas Mullaly thomas.mull...@gmail.com
  Date:   Sat Oct 9 11:02:17 2010 -0400

    urlmon: Implemented base case for CoInternetCombineIUri.

 introduces a new warning, use of uninitialized variable in the line
 marked HERE below.

  +static HRESULT combine_uri(Uri *base, Uri *relative, DWORD flags, IUri 
 **result
  +    Uri *ret;
  +    HRESULT hr;
  +    parse_data data;
  +
  +    /* Base case is when the relative Uri has a scheme name,
  +     * if it does, then 'result' will contain the same data
  +     * as the relative Uri.
  +     */
  +    if(relative-scheme_start  -1) {
  +        DWORD create_flags = 0;
  +
  +        memset(data, 0, sizeof(parse_data));
  +
  +        data.uri = SysAllocString(relative-raw_uri);
  +        if(!data.uri) {
  +            IUri_Release(URI(ret)); == HERE
  +            *result = NULL;
  +            return E_OUTOFMEMORY;
  +        }

 From all I can tell this is a legitimate warning, that is, the code
 really invokes undefined behavior.  Would you mind having a look?

 Gerald


Whoa! Good catch, I'll submit a new patch set here in a few minutes fixing that.

Thank you for the heads up.

-- 
Thomas Mullaly
thomas.mull...@gmail.com