[Patch v8 1/6] cli: command line parsing: allow default for keyword options

[Mark Walters <markwalters1009@gmail.com>]

This changes the parsing for "keyword" options so that if the option
is specified with no argument the argument is parsed as if it were
passed an empty string. This make it easier to add options to existing
boolean arguments (the existing --option can default to TRUE).
---
 command-line-arguments.c |   17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/command-line-arguments.c b/command-line-arguments.c
index 76b185f..b0a0dab 100644
--- a/command-line-arguments.c
+++ b/command-line-arguments.c
@@ -11,10 +11,15 @@
 */
 
 static notmuch_bool_t
-_process_keyword_arg (const notmuch_opt_desc_t *arg_desc, const char *arg_str) {
+_process_keyword_arg (const notmuch_opt_desc_t *arg_desc, char next, const char *arg_str) {
 
     const notmuch_keyword_t *keywords = arg_desc->keywords;
 
+    if (next == 0) {
+	/* No keyword given */
+	arg_str = "";
+    }
+
     while (keywords->name) {
 	if (strcmp (arg_str, keywords->name) == 0) {
 	    if (arg_desc->output_var) {
@@ -24,7 +29,10 @@ _process_keyword_arg (const notmuch_opt_desc_t *arg_desc, const char *arg_str) {
 	}
 	keywords++;
     }
-    fprintf (stderr, "unknown keyword: %s\n", arg_str);
+    if (next != 0)
+	fprintf (stderr, "unknown keyword: %s\n", arg_str);
+    else
+	fprintf (stderr, "option %s needs a keyword\n", arg_desc->name);
     return FALSE;
 }
 
@@ -99,7 +107,8 @@ parse_option (const char *arg,
 	     */
 	    if (next != '=' && next != ':' && next != 0) return FALSE;
 	    if (next == 0) {
-		if (try->opt_type != NOTMUCH_OPT_BOOLEAN)
+		if (try->opt_type != NOTMUCH_OPT_BOOLEAN &&
+		    try->opt_type != NOTMUCH_OPT_KEYWORD)
 		    return FALSE;
 	    } else {
 		if (value[0] == 0) return FALSE;
@@ -110,7 +119,7 @@ parse_option (const char *arg,
 
 	    switch (try->opt_type) {
 	    case NOTMUCH_OPT_KEYWORD:
-		return _process_keyword_arg (try, value);
+		return _process_keyword_arg (try, next, value);
 		break;
 	    case NOTMUCH_OPT_BOOLEAN:
 		return _process_boolean_arg (try, next, value);
-- 
1.7.9.1