Handle integer sequences when comparing file names

e.g. "d1m9" should come before "d1m10"

Quake/host_cmd.c

@@ -22,6 +22,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 
 #include "quakedef.h"
+#include "q_ctype.h"
 
 extern cvar_t	pausable;
 extern cvar_t	nomonsters;
@@ -52,6 +53,43 @@ void Host_Quit_f (void)
 //johnfitz -- extramaps management
 //==============================================================================
 
+/*
+==================
+FileList_Compare
+
+Case-insensitive string comparison that also handles integer sequences
+(e.g. d1m9 comes before d1m10)
+==================
+*/
+static int FileList_Compare (const char *s1, const char *s2)
+{
+	if (s1 == s2)
+		return 0;
+
+skip_prefix:
+	while (*s1 && !q_isdigit (*s1) && q_toupper (*s1) == q_toupper (*s2))
+	{
+		s1++;
+		s2++;
+		continue;
+	}
+
+	if (q_isdigit (*s1) && q_isdigit (*s2))
+	{
+		unsigned int num1 = *s1++ - '0';
+		unsigned int num2 = *s2++ - '0';
+		while (q_isdigit (*s1))
+			num1 = num1 * 10 + (*s1++ - '0');
+		while (q_isdigit (*s2))
+			num2 = num2 * 10 + (*s2++ - '0');
+		if (num1 != num2)
+			return num1 < num2 ? -1 : 1;
+		goto skip_prefix;
+	}
+
+	return q_toupper (*s1) - q_toupper (*s2);
+}
+
 /*
 ==================
 FileList_AddWithData
@@ -75,7 +113,7 @@ static void FileList_AddWithData (const char *name, const void *data, size_t dat
 
 	// insert each entry in alphabetical order
 	if (*list == NULL ||
-	    q_strcasecmp(item->name, (*list)->name) < 0) //insert at front
+	    FileList_Compare (item->name, (*list)->name) < 0) //insert at front
 	{
 		item->next = *list;
 		*list = item;
@@ -84,7 +122,7 @@ static void FileList_AddWithData (const char *name, const void *data, size_t dat
 	{
 		prev = *list;
 		cursor = (*list)->next;
-		while (cursor && (q_strcasecmp(item->name, cursor->name) > 0))
+		while (cursor && (FileList_Compare (item->name, cursor->name) > 0))
 		{
 			prev = cursor;
 			cursor = cursor->next;