[PATCH 5/5] lib: Separate all phrases indexed by _notmuch_message_gen_terms

[Austin Clements]

This adds a 100 termpos gap between all phrases indexed by
_notmuch_message_gen_terms.  This fixes a bug where terms from the end
of one header and the beginning of another header could match together
in a single phrase and a separate bug where term positions of
un-prefixed terms overlapped.

This fix only affects newly indexed messages.  Messages that are
already indexed won't benefit from this fix without re-indexing, but
the fix won't make things any worse for existing messages.
---
 lib/message.cc      | 9 +++++++--
 test/T080-search.sh | 2 --
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/message.cc b/lib/message.cc
index 9243b76..d0b7351 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -1023,16 +1023,21 @@ _notmuch_message_gen_terms (notmuch_message_t *message,
 	return NOTMUCH_PRIVATE_STATUS_NULL_POINTER;
 
     term_gen->set_document (message->doc);
-    term_gen->set_termpos (message->termpos);
 
     if (prefix_name) {
 	const char *prefix = _find_prefix (prefix_name);
 
+	term_gen->set_termpos (message->termpos);
 	term_gen->index_text (text, 1, prefix);
-	message->termpos = term_gen->get_termpos ();
+	/* Create a gap between this an the next terms so they don't
+	 * appear to be a phrase. */
+	message->termpos = term_gen->get_termpos () + 100;
     }
 
+    term_gen->set_termpos (message->termpos);
     term_gen->index_text (text);
+    /* Create a term gap, as above. */
+    message->termpos = term_gen->get_termpos () + 100;
 
     return NOTMUCH_PRIVATE_STATUS_SUCCESS;
 }
diff --git a/test/T080-search.sh b/test/T080-search.sh
index 3f6b565..05027fb 100755
--- a/test/T080-search.sh
+++ b/test/T080-search.sh
@@ -170,14 +170,12 @@ EOF
 notmuch new > /dev/null
 
 test_begin_subtest "headers do not have adjacent term positions"
-test_subtest_known_broken
 # Regression test for a bug where term positions for non-prefixed
 # terms weren't updated
 output=$(notmuch search id:termpos and '"com dest"')
 test_expect_equal "$output" ""
 
 test_begin_subtest "parts have non-overlapping term positions"
-test_subtest_known_broken
 output=$(notmuch search id:termpos and '"a y c"')
 test_expect_equal "$output" ""
 
-- 
2.0.0.rc2