Stop match earlier, and added some commentsrabbitmq_v3_6_3_milestone1

1 files changed, 10 insertions, 0 deletions

diff --git a/src/rabbit_exchange_type_headers.erl b/src/rabbit_exchange_type_headers.erl
index c9dedbbe95..444d507c7e 100644
--- a/src/rabbit_exchange_type_headers.erl
+++ b/src/rabbit_exchange_type_headers.erl
@@ -111,16 +111,26 @@ headers_match(Pattern = [{PK, _PT, _PV} | _], [{DK, _DT, _DV} | DRest],
 headers_match([{PK, _PT, _PV} | PRest], Data = [{DK, _DT, _DV} | _],
               _AllMatch, AnyMatch, MatchKind) when PK < DK ->
     headers_match(PRest, Data, false, AnyMatch, MatchKind);
+
+%% It's not properly specified, but a "no value" in a
+%% pattern field is supposed to mean simple presence of
+%% the corresponding data field. I've interpreted that to
+%% mean a type of "void" for the pattern field.
 headers_match([{PK, void, _PV} | PRest], [{DK, _DT, _DV} | DRest],
               AllMatch, _AnyMatch, MatchKind) when PK == DK ->
     headers_match(PRest, DRest, AllMatch, true, MatchKind);
+
+% Complete match, true with any, go next
 headers_match([{PK, _PT, PV} | PRest], [{DK, _DT, DV} | DRest],
               AllMatch, _AnyMatch, MatchKind) when PK == DK andalso PV == DV ->
     headers_match(PRest, DRest, AllMatch, true, MatchKind);
+
+% Value does not match, false with all, go next
 headers_match([{PK, _PT, _PV} | PRest], [{DK, _DT, _DV} | DRest],
               _AllMatch, AnyMatch, MatchKind) when PK == DK ->
     headers_match(PRest, DRest, false, AnyMatch, MatchKind).
 
+
 validate(_X) -> ok.
 create(_Tx, _X) -> ok.
 delete(_Tx, _X, _Bs) -> ok.