Sure, gcc knows to warn about this as well:
../../util/options.cc:175:17: warning: this statement may fall through [-Wimplicit-fallthrough=]
case 1: m.r = m.t;
~~~~^~~~~
../../util/options.cc:176:5: note: here
case 2: m.b = m.t;
^~~~
But HOLY SMOKES, look at clang -Weverything bot message:
options.cc:176:5: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
case 2: m.b = m.t;
^
options.cc:176:5: note: insert 'HB_FALLTHROUGH;' to silence this warning
case 2: m.b = m.t;
^
HB_FALLTHROUGH;
Right, it's telling me to insert "HB_FALLTHROUGH;" there!!!!!!!!!
9caa432d0c