copy the old save state before making a new savestate

command.c

@@ -1469,6 +1469,18 @@ static void command_event_save_state(const char *path,
       char *s, size_t len)
 {
    settings_t *settings = config_get_ptr();
+   char buf[PATH_MAX_LENGTH] = {0};
+
+   if (path_file_exists(path))
+   {
+      /* TODO: Fence with a setting */
+      strlcpy(buf, path, sizeof(buf));
+      snprintf(buf, sizeof(buf), "%s", path);
+      path_remove_extension(buf);
+      snprintf(buf, sizeof(buf), "%s.last", buf);
+
+      content_rename_state(path, buf);
+   }
 
    if (!content_save_state(path))
    {

content.h

@@ -51,6 +51,9 @@ bool content_load_state(const char *path);
 /* Save a state from memory to disk. */
 bool content_save_state(const char *path);
 
+/* Copy a save state. */
+bool content_rename_state(const char *origin, const char *dest);
+
 /* Load a state backup from disk to memory. */
 bool content_undo_load_state(const char *path);
 

tasks/task_save_state.c

@@ -18,10 +18,12 @@
 #include <sys/types.h>
 #include <string.h>
 #include <time.h>
+#include <unistd.h>
 #include <errno.h>
 
 #include <lists/string_list.h>
 #include <streams/file_stream.h>
+#include <file/file_path.h>
 
 #include "../core.h"
 #include "../msg_hash.h"
@@ -210,3 +212,19 @@ error:
    free(buf);
    return false;
 }
+
+bool content_rename_state(const char *origin, const char *dest)
+{
+   int ret = 0;
+   if (path_file_exists(dest))
+      unlink(dest);
+
+   ret = rename (origin, dest);
+   if (!ret)
+      return true;
+   else
+   {
+      RARCH_LOG ("Error %d renaming file %s", ret, origin);
+      return false;
+   }
+}