xlsx: fix reading/writing of number format 14.

It's locale dependent, despite what the spec says.  That's a dumb idea,
but it is not our dumb idea.

NEWS

@@ -3,6 +3,7 @@ Gnumeric 1.12.53
 Morten:
 	* Fix xlsx import of T.INV.
 	* Fix inter-process array paste problem.  [#634]
+	* Fix problem with xlsx number format 14.
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.52

plugins/excel/ChangeLog

+2022-05-22  Morten Welinder  <terra@gnome.org>
+
+	* xlsx-read.c (xlsx_get_num_fmt): Format 14 is locale dependent.
+	* xlsx-write.c (xlsx_load_buildin_num_formats): Ditto.
+
 2022-04-18  Morten Welinder <terra@gnome.org>
 
 	* Release 1.12.52

plugins/excel/xlsx-read.c

@@ -1059,7 +1059,7 @@ xlsx_get_num_fmt (GsfXMLIn *xin, char const *id)
 		/* 11 */ "0.00E+00",
 		/* 12 */ "# ?/?",
 		/* 13 */ "# ?""?/?""?",	/* silly trick to avoid using a trigraph */
-		/* 14 */ "mm-dd-yy",
+		/* 14 */ NULL, // Locale version of "mm-dd-yy"
 		/* 15 */ "d-mmm-yy",
 		/* 16 */ "d-mmm",
 		/* 17 */ "mmm-yy",
@@ -1172,13 +1172,20 @@ xlsx_get_num_fmt (GsfXMLIn *xin, char const *id)
 
 	/* builtins */
 	i = strtol (id, &end, 10);
-	if (end != id && *end == '\0' &&
-	    i >= 0 && i < (int) G_N_ELEMENTS (std_builtins) &&
-	    std_builtins[i] != NULL) {
+	if (end == id || *end != 0 || i < 0 || i >= (int) G_N_ELEMENTS (std_builtins))
+		i = -1;
+
+	if (i >= 0 && std_builtins[i] != NULL) {
 		res = go_format_new_from_XL (std_builtins[i]);
 		g_hash_table_replace (state->num_fmts, g_strdup (id), res);
+	} else if (i == 14) {
+		// Format 14 is locale dependent.  ms-excel-read.c suggests that maybe
+		// 15 should be too, but I cannot verify that anywhere.
+		res = go_format_new_magic (GO_FORMAT_MAGIC_SHORT_DATE);
+		g_hash_table_replace (state->num_fmts, g_strdup (id), res);
 	} else
 		xlsx_warning (xin, _("Undefined number format id '%s'"), id);
+
 	return res;
 }
 

plugins/excel/xlsx-write.c

@@ -548,7 +548,7 @@ xlsx_load_buildin_num_formats (GHashTable *hash)
 		/* 11 */ "0.00E+00",
 		/* 12 */ "# ?/?",
 		/* 13 */ "# ?""?/?""?",	/* silly trick to avoid using a trigraph */
-		/* 14 */ "mm-dd-yy",
+		/* 14 */ NULL, // Locale version of "mm-dd-yy"
 		/* 15 */ "d-mmm-yy",
 		/* 16 */ "d-mmm",
 		/* 17 */ "mmm-yy",
@@ -586,12 +586,20 @@ xlsx_load_buildin_num_formats (GHashTable *hash)
 		/* 49 */ "@"
 	};
 	unsigned int i;
+	GOFormat const *fmt;
 
 	g_return_if_fail (NUM_FORMAT_BASE > (int) G_N_ELEMENTS (std_builtins));
 
 	for (i = 1; i < G_N_ELEMENTS (std_builtins); i++)
 		if (std_builtins[i] != NULL)
 			g_hash_table_insert (hash, g_strdup (std_builtins[i]), GUINT_TO_POINTER (i));
+
+	// Format 14 is locale dependent.  ms-excel-read.c suggests that maybe
+	// 15 should be too, but I cannot verify that anywhere.
+	fmt = go_format_new_magic (GO_FORMAT_MAGIC_SHORT_DATE);
+	g_hash_table_insert (hash, g_strdup (go_format_as_XL (fmt)),
+			     GUINT_TO_POINTER (14));
+	go_format_unref (fmt);
 }
 
 static void