diff --git a/demux/demux_playlist.c b/demux/demux_playlist.c
index 17e2cd165b..a157c05deb 100644
--- a/demux/demux_playlist.c
+++ b/demux/demux_playlist.c
@@ -28,6 +28,7 @@
 #include "misc/charset_conv.h"
 #include "misc/thread_tools.h"
 #include "options/path.h"
+#include "player/core.h"
 #include "stream/stream.h"
 #include "osdep/io.h"
 #include "misc/natural_sort.h"
@@ -410,28 +411,17 @@ static int cmp_dir_entry(const void *a, const void *b)
     }
 }
 
-static bool has_str(bstr ext, char **list)
-{
-    if (!list)
-        return false;
-    while (*list) {
-        if (!bstrcasecmp0(ext, *list++))
-            return true;
-    }
-    return false;
-}
-
 static bool test_path(struct pl_parser *p, char *path, int autocreate)
 {
     if (autocreate & AUTO_ANY)
         return true;
 
     bstr ext = bstr_get_ext(bstr0(path));
-    if (autocreate & AUTO_VIDEO && has_str(ext, p->mp_opts->video_exts))
+    if (autocreate & AUTO_VIDEO && str_in_list(ext, p->mp_opts->video_exts))
         return true;
-    if (autocreate & AUTO_AUDIO && has_str(ext, p->mp_opts->audio_exts))
+    if (autocreate & AUTO_AUDIO && str_in_list(ext, p->mp_opts->audio_exts))
         return true;
-    if (autocreate & AUTO_IMAGE && has_str(ext, p->mp_opts->image_exts))
+    if (autocreate & AUTO_IMAGE && str_in_list(ext, p->mp_opts->image_exts))
         return true;
 
     return false;
@@ -521,11 +511,11 @@ static int parse_dir(struct pl_parser *p)
             autocreate = AUTO_VIDEO | AUTO_AUDIO | AUTO_IMAGE;
             break;
         case 3: // same
-            if (has_str(ext, p->mp_opts->video_exts)) {
+            if (str_in_list(ext, p->mp_opts->video_exts)) {
                 autocreate = AUTO_VIDEO;
-            } else if (has_str(ext, p->mp_opts->audio_exts)) {
+            } else if (str_in_list(ext, p->mp_opts->audio_exts)) {
                 autocreate = AUTO_AUDIO;
-            } else if (has_str(ext, p->mp_opts->image_exts)) {
+            } else if (str_in_list(ext, p->mp_opts->image_exts)) {
                 autocreate = AUTO_IMAGE;
             }
             break;
@@ -543,11 +533,11 @@ static int parse_dir(struct pl_parser *p)
         autocreate = AUTO_NONE;
         if (!p->opts->directory_filter || !p->opts->directory_filter[0])
             autocreate = AUTO_ANY;
-        if (has_str(bstr0("video"), p->opts->directory_filter))
+        if (str_in_list(bstr0("video"), p->opts->directory_filter))
             autocreate |= AUTO_VIDEO;
-        if (has_str(bstr0("audio"), p->opts->directory_filter))
+        if (str_in_list(bstr0("audio"), p->opts->directory_filter))
             autocreate |= AUTO_AUDIO;
-        if (has_str(bstr0("image"), p->opts->directory_filter))
+        if (str_in_list(bstr0("image"), p->opts->directory_filter))
             autocreate |= AUTO_IMAGE;
     }
     if (!stream->is_directory)
diff --git a/player/core.h b/player/core.h
index e37851e100..4ed7872a4f 100644
--- a/player/core.h
+++ b/player/core.h
@@ -565,6 +565,7 @@ void update_window_title(struct MPContext *mpctx, bool force);
 void error_on_track(struct MPContext *mpctx, struct track *track);
 int stream_dump(struct MPContext *mpctx, const char *source_filename);
 double get_track_seek_offset(struct MPContext *mpctx, struct track *track);
+bool str_in_list(bstr str, char **list);
 
 // osd.c
 void set_osd_bar(struct MPContext *mpctx, int type,
diff --git a/player/external_files.c b/player/external_files.c
index e1577a8607..996344405f 100644
--- a/player/external_files.c
+++ b/player/external_files.c
@@ -28,30 +28,19 @@
 #include "misc/language.h"
 #include "options/options.h"
 #include "options/path.h"
+#include "player/core.h"
 #include "external_files.h"
 
 // Needed for mp_might_be_subtitle_file
 char **sub_exts;
 
-static bool test_ext_list(bstr ext, char **list)
-{
-    if (!list)
-        goto done;
-    for (int n = 0; list[n]; n++) {
-        if (bstrcasecmp(bstr0(list[n]), ext) == 0)
-            return true;
-    }
-done:
-    return false;
-}
-
 static int test_ext(MPOpts *opts, bstr ext)
 {
-    if (test_ext_list(ext, opts->sub_auto_exts))
+    if (str_in_list(ext, opts->sub_auto_exts))
         return STREAM_SUB;
-    if (test_ext_list(ext, opts->audio_exts))
+    if (str_in_list(ext, opts->audio_exts))
         return STREAM_AUDIO;
-    if (test_ext_list(ext, opts->image_exts))
+    if (str_in_list(ext, opts->image_exts))
         return STREAM_VIDEO;
     return -1;
 }
@@ -70,7 +59,7 @@ static int test_cover_filename(bstr fname, char **cover_files)
 
 bool mp_might_be_subtitle_file(const char *filename)
 {
-    return test_ext_list(bstr_get_ext(bstr0(filename)), sub_exts);
+    return str_in_list(bstr_get_ext(bstr0(filename)), sub_exts);
 }
 
 void mp_update_subtitle_exts(struct MPOpts *opts)
diff --git a/player/misc.c b/player/misc.c
index 3f5da68dc8..036da5cf0b 100644
--- a/player/misc.c
+++ b/player/misc.c
@@ -343,3 +343,14 @@ const char *mp_status_str(enum playback_status st)
     default:                return "bug";
     }
 }
+
+bool str_in_list(bstr str, char **list)
+{
+    if (!list)
+        return false;
+    while (*list) {
+        if (!bstrcasecmp0(str, *list++))
+            return true;
+    }
+    return false;
+}