talloc:documentation - explain that "talloc_free" works also with "NULL" pointers

(talloc.c)
...
> static inline int _talloc_free_internal(void *ptr, const char *location)
> {
>        struct talloc_chunk *tc;
>
>        if (unlikely(ptr == NULL)) {
>                return -1;
>        }
>
>        tc = talloc_chunk_from_ptr(ptr);
...

Obviously this never had been documented before.

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/talloc/talloc_guide.txt b/lib/talloc/talloc_guide.txt
index 79387bfd46..a79fd03a83 100644
--- a/lib/talloc/talloc_guide.txt
+++ b/lib/talloc/talloc_guide.txt
@@ -117,10 +117,11 @@ children. You can call talloc_free() on any pointer returned by
 talloc().
 
 The return value of talloc_free() indicates success or failure, with 0
-returned for success and -1 for failure. The only possible failure
-condition is if the pointer had a destructor attached to it and the
-destructor returned -1. See talloc_set_destructor() for details on
-destructors.
+returned for success and -1 for failure. A possible failure condition
+is if the pointer had a destructor attached to it and the destructor
+returned -1. See talloc_set_destructor() for details on
+destructors. Likewise, if "ptr" is NULL, then the function will make
+no modifications and returns -1.
 
 If this pointer has an additional parent when talloc_free() is called
 then the memory is not actually released, but instead the most