'bp_core_avatar_default' filter is used twice, but for different purposes

[r-a-y]

In r10688, the 'bp_core_avatar_default' filter was introduced for a second time, but is used for a different purpose (see #6989). That filter is used in the generation of the Gravatar URL. We should rename this filter because it is causing a conflict when the real 'bp_core_avatar_default' filter is used. Perhaps rename the filter to 'bp_core_avatar_gravatar_default'?

The 'bp_core_avatar_default' filter was actually introduced back in BuddyPress 2.0 in r7769.

[imath]

Hi r-a-y,

Good catch 💪. Is there a way to know the purpose the filter was used for and then simply doing a doing_it_wrong feedback for one of the purpose or should we deprecate both filters ?

[imath]

In ​8347.patch I'm deprecating both filters and add some checks to see if the value is a default Gravatar or an URL to an avatar to eventually use the filtered value.

[imath]

In 12906:

Replace the bp_core_avatar_default filter with 2 new filters

The bp_core_avatar_default filter was used for two different purposes:

1. to edit the default BuddyPress avatar [7769].
2. to edit the default Gravatar [10688].

To avoid confusion or generate misleading behaviors, we are deprecating this filter in favor of 2 new filters :

1. Use bp_core_default_avatar to edit the default BuddyPress avatar.
2. Use bp_core_avatar_gravatar_default to edit the default Gravatar.

Props r-a-y

Fixes #8437