Re: [PATCH v2 7/7] unpack-trees: free cache_entry array members for merges

On Sun, Jun 2, 2013 at 6:06 PM, René Scharfe
[off-list ref] wrote:

Am 03.06.2013 00:38, schrieb Felipe Contreras:

quoted

On Sun, Jun 2, 2013 at 3:26 PM, René Scharfe
[off-list ref] wrote:

quoted

Am 02.06.2013 19:59, schrieb Felipe Contreras:

quoted

On Sun, Jun 2, 2013 at 12:54 PM, René Scharfe
[off-list ref] wrote:

quoted

Am 02.06.2013 19:25, schrieb Felipe Contreras:

quoted

On Sun, Jun 2, 2013 at 10:46 AM, René Scharfe
[off-list ref] wrote:

quoted

+               for (i = 0; i < n; i++) {
+                       struct cache_entry *ce = src[i + o->merge];
+                       if (ce != o->df_conflict_entry)

It's possible that ce is NULL, but you didn't add that check because
free(NULL) still works? Or because ce cannot be NULL?

If it's the former, I think it's clearer if we check that ce is not
NULL either way.

It is NULL if one tree misses an entry (e.g. a new or removed file).
free
handles NULL and we generally avoid duplicating its NULL-check.

Yeah, but I can see somebody adding code inside that 'if' clause to
print the cache entry, and see a crash only to wonder what's going on.
And to save what? 5 characters?

The person adding code that depends on ce not being NULL needs to add
that
check as well.  Let's not worry too much about future changes that may or
(more likely IMHO) may not be done.  The test suite covers this case
multiple times, so such a mistake doesn't have a realistic chance to hit
master.

What do we gain by not doing this? 5 less characters?

By following the convention of not checking for NULL when freeing,

That's not what I asked.

I didn't say we should do 'if (ce) free(ce);' instead of 'free(ce);' I
said we should do 'if (cd && ce != o->df_conflict_entry)' instead of
'if (ce != o->df_conflict_entry)'.

There's no reason not to.

-- 
Felipe Contreras