[PATCH] lib: don't compile sexp: prefix if no sfsexp library

[David Bremner <david@tethera.net>]

As Michael Gruber pointed out, the build is otherwise broken on
systems without libsfsexp.
---
 lib/prefix.cc  | 4 ++++
 lib/sexp-fp.cc | 3 +++
 lib/sexp-fp.h  | 2 ++
 3 files changed, 9 insertions(+)

diff --git a/lib/prefix.cc b/lib/prefix.cc
index 06e2333a..538a2dd1 100644
--- a/lib/prefix.cc
+++ b/lib/prefix.cc
@@ -61,8 +61,10 @@ prefix_t prefix_table[] = {
       NOTMUCH_FIELD_PROCESSOR },
     { "query",                  NULL,           NOTMUCH_FIELD_EXTERNAL |
       NOTMUCH_FIELD_PROCESSOR },
+#if HAVE_SFSEXP
     { "sexp",                  NULL,            NOTMUCH_FIELD_EXTERNAL |
       NOTMUCH_FIELD_PROCESSOR },
+#endif
     { "from",                   "XFROM",        NOTMUCH_FIELD_EXTERNAL |
       NOTMUCH_FIELD_PROBABILISTIC |
       NOTMUCH_FIELD_PROCESSOR },
@@ -141,8 +143,10 @@ _setup_query_field (const prefix_t *prefix, notmuch_database_t *notmuch)
 	    fp = (new QueryFieldProcessor (*notmuch->query_parser, notmuch))->release ();
 	else if (STRNCMP_LITERAL (prefix->name, "thread") == 0)
 	    fp = (new ThreadFieldProcessor (*notmuch->query_parser, notmuch))->release ();
+#if HAVE_SFSEXP
 	else if (STRNCMP_LITERAL (prefix->name, "sexp") == 0)
 	    fp = (new SexpFieldProcessor (notmuch))->release ();
+#endif
 	else
 	    fp = (new RegexpFieldProcessor (prefix->name, prefix->flags,
 					    *notmuch->query_parser, notmuch))->release ();
diff --git a/lib/sexp-fp.cc b/lib/sexp-fp.cc
index ed26f6ec..eeb8be98 100644
--- a/lib/sexp-fp.cc
+++ b/lib/sexp-fp.cc
@@ -21,6 +21,8 @@
  */
 
 #include "database-private.h"
+
+#if HAVE_SFSEXP
 #include "sexp-fp.h"
 #include <iostream>
 
@@ -38,3 +40,4 @@ SexpFieldProcessor::operator() (const std::string & query_string)
     return output;
 
 }
+#endif /* HAVE_SFSEXP */
diff --git a/lib/sexp-fp.h b/lib/sexp-fp.h
index 341dfa7e..0e55b961 100644
--- a/lib/sexp-fp.h
+++ b/lib/sexp-fp.h
@@ -23,6 +23,7 @@
 #ifndef NOTMUCH_SEXP_FP_H
 #define NOTMUCH_SEXP_FP_H
 
+#if HAVE_SFSEXP
 #include <xapian.h>
 #include "notmuch.h"
 
@@ -38,4 +39,5 @@ public:
     Xapian::Query operator() (const std::string & query_string);
 };
 
+#endif /* HAVE_SFSEXP */
 #endif /* NOTMUCH_SEXP_FP_H */
-- 
2.35.1