[libsoup] session: Document the context callbacks are invoked on

[Patrick Griffis <pgriffis src gnome org>]

commit 892fac1f315559b19f84a0206293b5f7e51039f8
Author: Patrick Griffis <pgriffis igalia com>
Date:   Mon Jan 10 17:53:30 2022 +0000

    session: Document the context callbacks are invoked on

 libsoup/soup-session.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/libsoup/soup-session.c b/libsoup/soup-session.c
index ce9bbf9d..319174f3 100644
--- a/libsoup/soup-session.c
+++ b/libsoup/soup-session.c
@@ -64,6 +64,9 @@
  * for %SOUP_TYPE_AUTH_BASIC and %SOUP_TYPE_AUTH_DIGEST. Additionally,
  * sessions using the plain #SoupSession class (rather than one of its deprecated
  * subtypes) have a #SoupContentDecoder by default.
+ *
+ * Note that all async methods will invoke their callbacks on the thread-default
+ * context at the time of the function call.
  **/
 
 /**