Fix the bibliography DOI output when the hyperref package is not loaded.

The last attempt at adding hyperref support for DOIs worked, but it
broke things when the hyperref package isn't loaded. This commit fixes
it by conditionally defining a no-op \href in the absense of the
hyperref package.

Now that I understand what's going on a little bit better, I was also
able to eliminate some of the urlbst boilerplate.

diff --git a/mjo.bst b/mjo.bst
index 105ec77b607b891ec7c03c90044da1a72b726971..5a09e3d0467c59b8f407273a735e24271f2201c9 100644 (file)
--- a/mjo.bst
+++ b/mjo.bst
@@ -68,12 +68,10 @@ ENTRY
   { label }
 
 STRINGS { doiprefix doiurl }
-INTEGERS { hrefform }
 FUNCTION {init.doi.variables}
 {
   "http://dx.doi.org/" 'doiurl := % prefix to make URL from DOI
   "doi:" 'doiprefix :=      % text prefix printed before DOI ref
-  #2 'hrefform :=           % 0=no crossrefs; 1=hypertex xrefs; 2=hyperref refs
 }
 INTEGERS { output.state before.all mid.sentence after.sentence after.block }
 FUNCTION {init.state.consts}
@@ -491,33 +489,8 @@ FUNCTION {format.issn}
   if$
 }
 
-FUNCTION {make.href.null}
-{
-  pop$
-}
-
-FUNCTION {make.href.hypertex}
-{
-  "\special {html:<a href=" quote$ *
-  swap$ * quote$ * "> }" * swap$ *
-  "\special {html:</a>}" *
-}
-
-FUNCTION {make.href.hyperref}
-{
-  "\href {" swap$ * "} {\path{" * swap$ * "}}" *
-}
-
 FUNCTION {make.href}
-{ hrefform #2 =
-    'make.href.hyperref      % hrefform = 2
-    { hrefform #1 =
-        'make.href.hypertex  % hrefform = 1
-        'make.href.null      % hrefform = 0 (or anything else)
-      if$
-    }
-  if$
-}
+{ "\href {" swap$ * "} {\path{" * swap$ * "}}" * }
 
 FUNCTION {format.doi}
 { doi empty$
@@ -1483,6 +1456,10 @@ FUNCTION {begin.bib}
   write$ newline$
   "  \providecommand{\doi}{doi:\discretionary{}{}{}\begingroup \urlstyle{rm}\Url}\fi"
   write$ newline$
+  "\expandafter\ifx\csname href\endcsname\relax"
+  write$ newline$
+  "  \def\href#1#2{#2} \def\path#1{#1}\fi"
+  write$ newline$
 }
 EXECUTE {begin.bib}
 EXECUTE {init.doi.variables}