Decode local paths from drop payloads

Drops arrive as a CRLF-separated text/uri-list of file URLs, so every
consumer percent-decodes them; wsap_term does it in its own drop code.

yasl_drop_next_path() walks the list and returns one decoded local path
at a time. It accepts file:///, file:/, and file://localhost or this
machine's name, ends the path at '?' or '#', and skips comments, other
schemes, remote hosts, malformed escapes, and escaped NUL bytes. A buffer
that is too small leaves the cursor in place, like the other functions
that fill a buffer.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/yasl/yasl.h b/include/yasl/yasl.h
index 5946816..f798304 100644
--- a/include/yasl/yasl.h
+++ b/include/yasl/yasl.h
@@ -777,6 +777,23 @@ YASL_API bool yasl_surface_present(struct yasl_surface *s, const struct yasl_fra
  */
 YASL_API bool yasl_surface_poll_event(struct yasl_surface *s, struct yasl_event *ev);
 /**
+ * Decode the next local file path from a YASL_EVENT_DROP payload.
+ * @param cursor Required in/out position in the NUL-terminated list. Start it
+ * at event.text.data; a NULL *cursor returns zero.
+ * @param out Output for the NUL-terminated path, or NULL when cap is zero.
+ * @param cap Size of out in bytes.
+ * @return Path length in bytes, excluding the NUL, or zero when no paths remain.
+ * When the result is less than cap, out holds the path and *cursor moves past
+ * it. Otherwise out and *cursor are unchanged; call again with a buffer of at
+ * least the result plus one.
+ * Accepts file:///path, file:/path, and file://host/path when host is
+ * localhost or this machine's name. Percent escapes decode to raw bytes, and
+ * a '?' or '#' ends the path. Skips blank lines, comments, other schemes,
+ * other hosts, and lines with a malformed escape or an escaped NUL. May be
+ * called from any thread.
+ */
+YASL_API size_t yasl_drop_next_path(const char **cursor, char *out, size_t cap);
+/**
  * Copy the last frame presented from the surface's CPU target.
  * @param s Surface.
  * @param out Output for size->x * size->y premultiplied ARGB8888 pixels with