input/rewind: enable the "rewind" wrapper for all non-seekable streams

Don't limit the "rewind" input plugin to CURL streams.

Makefile.am

@@ -586,11 +586,11 @@ INPUT_SRC = \
 	src/input_init.c \
 	src/input_registry.c \
 	src/input_stream.c \
+	src/input/rewind_input_plugin.c \
 	src/input/file_input_plugin.c
 
 if ENABLE_CURL
 INPUT_SRC += src/input/curl_input_plugin.c \
-	src/input/rewind_input_plugin.c \
 	src/icy_metadata.c
 endif
 

src/input/rewind_input_plugin.c

@@ -221,9 +221,8 @@ input_rewind_open(struct input_stream *is)
 	assert(is != NULL);
 	assert(is->offset == 0);
 
-	if (is->plugin != &input_plugin_curl)
-		/* due to limitations in the input_plugin API, we only
-		   (explicitly) support the CURL input plugin */
+	if (is->seekable)
+		/* seekable resources don't need this plugin */
 		return is;
 
 	c = g_new(struct input_rewind, 1);

src/input/rewind_input_plugin.h

@@ -31,19 +31,7 @@
 
 struct input_stream;
 
-#ifdef ENABLE_CURL
-
 struct input_stream *
 input_rewind_open(struct input_stream *is);
 
-#else
-
-static inline struct input_stream *
-input_rewind_open(struct input_stream *is)
-{
-	return is;
-}
-
-#endif
-
 #endif