i18n: parseopt: lookup help and argument translations when showing usage

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/parse-options.h b/parse-options.h
index da999f8..77a4a8b 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -66,12 +66,14 @@
  *
  * `argh`::
  *   token to explain the kind of argument this option wants. Keep it
- *   homogeneous across the repository.
+ *   homogeneous across the repository. Should be wrapped by N_() for
+ *   translation.
  *
  * `help`::
  *   the short help associated to what the option does.
  *   Must never be NULL (except for OPTION_END).
  *   OPTION_GROUP uses this pointer to store the group header.
+ *   Should be wrapped by N_() for translation.
  *
  * `flags`::
  *   mask of parse_opt_option_flags.
@@ -128,7 +130,7 @@
 #define OPT_BOOL(s, l, v, h)        OPT_SET_INT(s, l, v, h, 1)
 #define OPT_SET_PTR(s, l, v, h, p)  { OPTION_SET_PTR, (s), (l), (v), NULL, \
 				      (h), PARSE_OPT_NOARG, NULL, (p) }
-#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), "n", (h) }
+#define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), N_("n"), (h) }
 #define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
 #define OPT_STRING_LIST(s, l, v, a, h) \
 				    { OPTION_CALLBACK, (s), (l), (v), (a), \
@@ -136,7 +138,7 @@
 #define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
 				      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
 #define OPT_DATE(s, l, v, h) \
-	{ OPTION_CALLBACK, (s), (l), (v), "time",(h), 0, \
+	{ OPTION_CALLBACK, (s), (l), (v), N_("time"),(h), 0,	\
 	  parse_opt_approxidate_cb }
 #define OPT_CALLBACK(s, l, v, a, h, f) \
 	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }
@@ -144,21 +146,22 @@
 	{ OPTION_NUMBER, 0, NULL, (v), NULL, (h), \
 	  PARSE_OPT_NOARG | PARSE_OPT_NONEG, (f) }
 #define OPT_FILENAME(s, l, v, h)    { OPTION_FILENAME, (s), (l), (v), \
-				       "file", (h) }
+				       N_("file"), (h) }
 #define OPT_COLOR_FLAG(s, l, v, h) \
-	{ OPTION_CALLBACK, (s), (l), (v), "when", (h), PARSE_OPT_OPTARG, \
+	{ OPTION_CALLBACK, (s), (l), (v), N_("when"), (h), PARSE_OPT_OPTARG, \
 		parse_opt_color_flag_cb, (intptr_t)"always" }
 
 #define OPT_NOOP_NOARG(s, l) \
 	{ OPTION_CALLBACK, (s), (l), NULL, NULL, \
-	  "no-op (backward compatibility)", \
+	  N_("no-op (backward compatibility)"),		\
 	  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, parse_opt_noop_cb }
 
 /* Deprecated synonym */
 #define OPT_BOOLEAN OPT_COUNTUP
 
 /* parse_options() will filter out the processed options and leave the
- * non-option arguments in argv[].
+ * non-option arguments in argv[]. usagestr strings should be marked
+ * for translation with N_().
  * Returns the number of arguments left in argv[].
  */
 extern int parse_options(int argc, const char **argv, const char *prefix,
@@ -222,15 +225,15 @@
 #define OPT__VERBOSE(var, h)  OPT_BOOLEAN('v', "verbose", (var), (h))
 #define OPT__QUIET(var, h)    OPT_BOOLEAN('q', "quiet",   (var), (h))
 #define OPT__VERBOSITY(var) \
-	{ OPTION_CALLBACK, 'v', "verbose", (var), NULL, "be more verbose", \
+	{ OPTION_CALLBACK, 'v', "verbose", (var), NULL, N_("be more verbose"), \
 	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }, \
-	{ OPTION_CALLBACK, 'q', "quiet", (var), NULL, "be more quiet", \
+	{ OPTION_CALLBACK, 'q', "quiet", (var), NULL, N_("be more quiet"), \
 	  PARSE_OPT_NOARG, &parse_opt_verbosity_cb, 0 }
 #define OPT__DRY_RUN(var, h)  OPT_BOOLEAN('n', "dry-run", (var), (h))
 #define OPT__FORCE(var, h)    OPT_BOOLEAN('f', "force",   (var), (h))
 #define OPT__ABBREV(var)  \
-	{ OPTION_CALLBACK, 0, "abbrev", (var), "n", \
-	  "use <n> digits to display SHA-1s", \
+	{ OPTION_CALLBACK, 0, "abbrev", (var), N_("n"),	\
+	  N_("use <n> digits to display SHA-1s"),	\
 	  PARSE_OPT_OPTARG, &parse_opt_abbrev_cb, 0 }
 #define OPT__COLOR(var, h) \
 	OPT_COLOR_FLAG(0, "color", (var), (h))