lib: do not phrase parse prefixed bracketed subexpressions

Since Xapian does not preserve quotes when passing the subquery to a
field processor, we have to make a guess as to what the user
intended. Here the added assumption is that a string surrounded by
parens is not intended to be a phrase.

doc/man7/notmuch-search-terms.rst

@@ -275,11 +275,13 @@ the same phrase.
 - a.list.of.words
 
 Both parenthesised lists of terms and quoted phrases are ok with
-probabilistic prefixes such as **to:**, **from:**, and **subject:**. In particular
+probabilistic prefixes such as **to:**, **from:**, and **subject:**.
+For prefixes supporting regex search, the parenthesised list should be
+quoted.  In particular
 
 ::
 
-   subject:(pizza free)
+   subject:"(pizza free)"
 
 is equivalent to
 

lib/regexp-fields.cc

@@ -227,7 +227,8 @@ RegexpFieldProcessor::operator() (const std::string & str)
 	     * phrase parsing, when possible */
 	    std::string query_str;
 
-	    if (*str.rbegin () != '*' || str.find (' ') != std::string::npos)
+	    if ((str.at (0) != '(' || *str.rbegin () != ')') &&
+		(*str.rbegin () != '*' || str.find (' ') != std::string::npos))
 		query_str = '"' + str + '"';
 	    else
 		query_str = str;

test/T650-regexp-query.sh

@@ -66,23 +66,30 @@ EOF
 test_expect_equal_file EXPECTED OUTPUT
 
 test_begin_subtest "bracketed subject search (with dquotes)"
-test_subtest_known_broken
 notmuch search subject:notmuch and subject:show > EXPECTED
 notmuch search 'subject:"(show notmuch)"' > OUTPUT
 test_expect_equal_file_nonempty EXPECTED OUTPUT
 
 test_begin_subtest "bracketed subject search (with dquotes and operator 'or')"
-test_subtest_known_broken
 notmuch search subject:notmuch or subject:show > EXPECTED
 notmuch search 'subject:"(notmuch or show)"' > OUTPUT
 test_expect_equal_file_nonempty EXPECTED OUTPUT
 
 test_begin_subtest "bracketed subject search (with dquotes and operator 'and')"
-test_subtest_known_broken
 notmuch search subject:notmuch and subject:show > EXPECTED
 notmuch search 'subject:"(notmuch and show)"' > OUTPUT
 test_expect_equal_file_nonempty EXPECTED OUTPUT
 
+test_begin_subtest "bracketed subject search (with phrase, operator 'or')"
+notmuch search 'subject:"mailing list"' or subject:FreeBSD > EXPECTED
+notmuch search  'subject:"(""mailing list"" or FreeBSD)"' > OUTPUT
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
+test_begin_subtest "bracketed subject search (with phrase, operator 'and')"
+notmuch search  search 'subject:"notmuch show"' and subject:commands > EXPECTED
+notmuch search  'subject:"(""notmuch show"" and commands)"' > OUTPUT
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
 test_begin_subtest "xapian wildcard search for from:"
 notmuch search --output=messages 'from:cwo*' > OUTPUT
 test_expect_equal_file cworth.msg-ids OUTPUT