input_stream: use "goffset" instead of "off_t"

The "off_t" type may change when you enable or disable large file
support on 32 bit platforms.  This caused severe ABI problems within
MPD when we enabled LFS for the first time: two sources included
config.h and sys/types.h in different order, and had different off_t
sizes - leading to memory corruption because of ABI incompatibility.
This patch attempts to get rid of all public "off_t" uses: it removes
"off_t" from the input_stream ABI/API, and switches to GLib's 64 bit
"goffset" type.  This may hurt 32 bit embedded platforms a tiny bit,
but that's not even measurable.

src/input/curl_input_plugin.c

@@ -42,7 +42,7 @@
 #define G_LOG_DOMAIN "input_curl"
 
 /** rewinding is possible after up to 64 kB */
-static const off_t max_rewind_size = 64 * 1024;
+static const goffset max_rewind_size = 64 * 1024;
 
 /**
  * Buffers created by input_curl_writefunction().
@@ -425,7 +425,7 @@ input_curl_read(struct input_stream *is, void *ptr, size_t size)
 #ifndef NDEBUG
 	if (c->rewind != NULL &&
 	    (!g_queue_is_empty(c->rewind) || is->offset == 0)) {
-		off_t offset = 0;
+		goffset offset = 0;
 		struct buffer *buffer;
 
 		for (GList *list = g_queue_peek_head_link(c->rewind);
@@ -474,11 +474,11 @@ input_curl_read(struct input_stream *is, void *ptr, size_t size)
 	if (icy_defined(&c->icy_metadata))
 		copy_icy_tag(c);
 
-	is->offset += (off_t)nbytes;
+	is->offset += (goffset)nbytes;
 
 #ifndef NDEBUG
 	if (rewind_buffers != NULL) {
-		off_t offset = 0;
+		goffset offset = 0;
 		struct buffer *buffer;
 
 		for (GList *list = g_queue_peek_head_link(c->rewind);
@@ -772,7 +772,7 @@ input_curl_can_rewind(struct input_stream *is)
 	/* rewind is possible if this is the very first buffer of the
 	   resource */
 	buffer = (struct buffer*)g_queue_peek_head(c->buffers);
-	return (off_t)buffer->consumed == is->offset;
+	return (goffset)buffer->consumed == is->offset;
 }
 
 static void
@@ -780,7 +780,7 @@ input_curl_rewind(struct input_stream *is)
 {
 	struct input_curl *c = is->data;
 #ifndef NDEBUG
-	off_t offset = 0;
+	goffset offset = 0;
 #endif
 
 	assert(c->rewind != NULL);
@@ -818,7 +818,7 @@ input_curl_rewind(struct input_stream *is)
 }
 
 static bool
-input_curl_seek(struct input_stream *is, off_t offset, int whence)
+input_curl_seek(struct input_stream *is, goffset offset, int whence)
 {
 	struct input_curl *c = is->data;
 	bool ret;
@@ -884,7 +884,7 @@ input_curl_seek(struct input_stream *is, off_t offset, int whence)
 		buffer = (struct buffer *)g_queue_pop_head(c->buffers);
 
 		length = buffer->size - buffer->consumed;
-		if (offset - is->offset < (off_t)length)
+		if (offset - is->offset < (goffset)length)
 			length = offset - is->offset;
 
 		buffer = consume_buffer(buffer, length, rewind_buffers);

src/input/file_input_plugin.c

@@ -17,6 +17,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include "config.h" /* must be first for large file support */
 #include "input/file_input_plugin.h"
 #include "input_plugin.h"
 
@@ -92,11 +93,11 @@ input_file_open(struct input_stream *is, const char *filename)
 }
 
 static bool
-input_file_seek(struct input_stream *is, off_t offset, int whence)
+input_file_seek(struct input_stream *is, goffset offset, int whence)
 {
 	int fd = GPOINTER_TO_INT(is->data);
 
-	offset = lseek(fd, offset, whence);
+	offset = (goffset)lseek(fd, (off_t)offset, whence);
 	if (offset < 0) {
 		is->error = errno;
 		return false;

src/input/lastfm_input_plugin.c

@@ -285,7 +285,7 @@ lastfm_input_eof_wrap(struct input_stream *is)
 }
 
 static bool
-lastfm_input_seek_wrap(struct input_stream *is, off_t offset, int whence)
+lastfm_input_seek_wrap(struct input_stream *is, goffset offset, int whence)
 {
 	bool ret;
 	struct lastfm_input *d = is->data;

src/input/mms_input_plugin.c

@@ -110,7 +110,7 @@ input_mms_buffer(G_GNUC_UNUSED struct input_stream *is)
 
 static bool
 input_mms_seek(G_GNUC_UNUSED struct input_stream *is,
-	       G_GNUC_UNUSED off_t offset, G_GNUC_UNUSED int whence)
+	       G_GNUC_UNUSED goffset offset, G_GNUC_UNUSED int whence)
 {
 	return false;
 }