Created attachment 12164 [details] [review]
Return p->name instead of p->value (untested)

Here is a little patch to change p->value to p->name in 
_XimSetIMValueData() and _XimGetIMValueData()

My original program does the following:

    char *name;

    static const char *invalid = "INVALID";

    void *arg = (void *) 0x004c754e; /* "NuL" on i386 arch */

    XIMValuesList *imvl = NULL;
    XIMStyles *ims = NULL;

    /* retrieve some values, and get an error */
    name = XGetIMValues(im, 
			XNQueryIMValuesList, &imvl, 
			XNQueryInputStyle, &ims,
			invalid, &arg, 
			NULL);
    if (name != NULL) {
      /* 
       * name should point to the name 
       * which was not retrieved, eg. "INVALID"
       */
      printf("XGetIMValues() returned: %p '%s'\n"
	     "invalid name: %p '%s'\n"
	     "invalid arg:  %p\n", 
	     name, name, 
	     invalid, invalid, 
	     &arg);
    }

And print:

XGetIMValues() returned: 0xbf8d1d34 'NuL'
invalid name: 0x8048adf 'INVALID'
invalid arg:  0xbf8d1d34

(In reply to comment #2)
This doesn't compile. Can you an example that compiles so I can check to see if this is still an issue?

Created attachment 41259 [details]
Working test case for XGetIMValues()

(In reply to comment #3)
> This doesn't compile. Can you an example that compiles so I can check to see if
> this is still an issue?

Here's a complete test case which demonstrate the problem:

  $ gcc -Wall -Wextra test-XGetIMValues.c -o test-XGetIMValues -lX11 
  $ ./test-XGetIMValues 
  XLib support current locale
  Current locale modifier '@im=none'
  XGetIMValues() returned: 0x7fff220d5628 'NuL'
        invalid name was : 0x400db8 'INVALID'
        invalid arg  was : 0x7fff220d5628
  ERROR: XGetIMValues() returned address of argument instead of its name
  ERROR: valid function return would be: 0x400db8 'INVALID'

As you can see XGetIMValues() returns the argument and not its name.

XGetIMValues() man page :

  The XGetIMValues function presents a variable argument list programming 
  interface for querying properties or features of the specified input method.  
  This function returns NULL if it succeeds; otherwise, it returns the name of 
  the first argument that could not be obtained.

(In reply to comment #4)

It was tested on Fedora Core 14 against libX11 1.3.4.

Can you please send your patch to xorg-devel for review?

Thanks.

Pushed the fix, thanks.