Re: [PATCH 54/67] color: add overflow checks for parsing colors

Jeff King [off-list ref] writes:

On Fri, Sep 18, 2015 at 02:54:11PM -0400, Eric Sunshine wrote:

quoted

quoted

@@ -224,12 +227,18 @@ int color_parse_mem(const char *value, int value_len, char *dst)
                        goto bad;
        }

+#define OUT(x) do { \
+       if (dst == end) \
+               die("BUG: color parsing ran out of space"); \
+       *dst++ = (x); \
+} while(0)

Hmm, can we have an #undef OUT before the #define OUT(...), or choose
a less conflict-likely name? In particular, I'm thinking about
preprocessor namespace pollution arising from sources out of our
control, such as was the case with 414382f (ewah/bitmap: silence
warning about MASK macro redefinition, 2015-06-03).

Sure. I wouldn't think any headers would be dumb enough to define
something as short and common as OUT. But then I would have said the
same about MASK. ;)

I added an #undef, and I added an #undef at the end of the function, as
well (to clean up after ourselves).

A tangent.  quote.c does EMIT semi-carefully, but gets sloppy when
it does a similar thing for EMITBUF.

Perhaps it should go to somebody's low-hanging-fruit list ;-)