[xml] gcc 4.6 gives error in xpath.c when boundary checking enabled




Hi,

I am not sure if this issue has already been reported. I did a quick search and did not find a report though.

When I enable boundary check in gcc 4.6 (-Werror=array-bounds), I get an error:

libxml2/xpath.c: In function 'xmlXPathCastNumberToString':
libxml2/xpath.c:2810:7: error: array subscript is above array bounds [-Werror=array-bounds]

Note that I am using an arm version of the compiler. Looking at the code, the error is here:

size = snprintf(work, sizeof(work), "%0.*f",
fraction_place, number);
   }

   /* Remove fractional trailing zeroes */
   after_fraction = work + size;
   ptr = after_fraction;
   while (*(--ptr) == '0')
;
   if (*ptr != '.')
       ptr++;
   while ((*ptr++ = *after_fraction++) != 0);

   /* Finally copy result back to caller */
   size = strlen(work) + 1;
   if (size > buffersize  ) {
work[buffersize - 1] = 0;         <------------------
size = buffersize;
   }

I don't necessarily see a problem in the code since (due to snprintf above) when if is entered buffersize will be guaranteed to be less than or equal to size of work, but I wanted to make sure. Do you see any issues in the code?

 Thanks in advance,

Note: I think my first email did not go, so sorry if this is received as a duplicate.
-Selim



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