Merge branch 'master' into v2.1

diff --cc src/lj_debug.c
index bb77ad77620d01928361c272c78649b675d5ed61,effb4841e62a07cda49a584824ffda4a49e7664a..180748745af6d7d7364c207384fb9759b220a2f6
--- 1/src/lj_debug.c
--- 2/src/lj_debug.c
+++ b/src/lj_debug.c
@@@ -451,10 -460,10 +451,10 @@@ int lj_debug_getinfo(lua_State *L, cons
        BCLine firstline = pt->firstline;
        GCstr *name = proto_chunkname(pt);
        ar->source = strdata(name);
 -      lj_debug_shortname(ar->short_src, name);
 +      lj_debug_shortname(ar->short_src, name, pt->firstline);
        ar->linedefined = (int)firstline;
        ar->lastlinedefined = (int)(firstline + pt->numline);
-       ar->what = firstline ? "Lua" : "main";
+       ar->what = (firstline || !pt->numline) ? "Lua" : "main";
        } else {
        ar->source = "=[C]";
        ar->short_src[0] = '[';