bug#8211: uninitialized variable in detect_coding_iso_2022's end-of-composition code

[Andreas Schwab <schwab@linux-m68k.org>]

Paul Eggert <eggert@cs.ucla.edu> writes:

> I found this problem by compiling Emacs with GCC's -Wuninitialized flag.
>
> The following code in the Emacs trunk src/coding.c's
> detect_coding_iso_2022 function apparently uses an uninitialized variable:
>
>           ...
>           else if (c == '1')
>             {
>               /* End of composition.  */
>               if (composition_count < 0
>                   || composition_count > MAX_COMPOSITION_COMPONENTS)
>                 /* Invalid */
>                 break;
>               composition_count = -1;
>               found |= CATEGORY_MASK_ISO;
>             }
>           else
>             ...
>
>           /* We found a valid designation sequence for CHARSET.  */
>           rejected |= CATEGORY_MASK_ISO_8BIT;
>           if (SAFE_CHARSET_P (&coding_categories[coding_category_iso_7],
>                               id))
>             found |= CATEGORY_MASK_ISO_7;
>
> The problem is that the "else if (c == '1')" branch does not initialize
> the local variable "id", but the second "if" test uses that variable.

I think it just lacks a break.  ESC '1' is not a designation sequence.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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