rtspsink: use version template in user-agent property

Avoids documentation churn when the version changes.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5090>

subprojects/gst-rtsp-server/docs/plugins/gst_plugins_cache.json

@@ -333,7 +333,7 @@
                         "construct": false,
                         "construct-only": false,
                         "controllable": false,
-                        "default": "GStreamer/1.23.0.1",
+                        "default": "GStreamer/{VERSION}",
                         "mutable": "null",
                         "readable": true,
                         "type": "gchararray",

subprojects/gst-rtsp-server/gst/glib-compat-private.h

@@ -0,0 +1,83 @@
+/*
+ * glib-compat.c
+ * Functions copied from glib 2.10
+ *
+ * Copyright 2005 David Schleef <ds@schleef.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GLIB_COMPAT_PRIVATE_H__
+#define __GLIB_COMPAT_PRIVATE_H__
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+/* copies */
+
+#if !GLIB_CHECK_VERSION(2,68,0)
+#ifndef g_string_replace
+#define g_string_replace gst_g_string_replace
+#endif
+
+static inline guint
+gst_g_string_replace (GString     *string,
+                      const gchar *find,
+                      const gchar *replace,
+                      guint        limit)
+{
+  gsize f_len, r_len, pos;
+  gchar *cur, *next;
+  guint n = 0;
+
+  g_return_val_if_fail (string != NULL, 0);
+  g_return_val_if_fail (find != NULL, 0);
+  g_return_val_if_fail (replace != NULL, 0);
+
+  f_len = strlen (find);
+  r_len = strlen (replace);
+  cur = string->str;
+
+  while ((next = strstr (cur, find)) != NULL)
+    {
+      pos = next - string->str;
+      g_string_erase (string, pos, f_len);
+      g_string_insert (string, pos, replace);
+      cur = string->str + pos + r_len;
+      n++;
+      /* Only match the empty string once at any given position, to
+       * avoid infinite loops */
+      if (f_len == 0)
+        {
+          if (cur[0] == '\0')
+            break;
+          else
+            cur++;
+        }
+      if (n == limit)
+        break;
+    }
+
+  return n;
+}
+#endif /* GLIB_CHECK_VERSION */
+
+/* adaptations */
+
+G_END_DECLS
+
+#endif

subprojects/gst-rtsp-server/gst/rtsp-sink/gstrtspclientsink.c

@@ -101,6 +101,8 @@
 
 #include "gstrtspclientsink.h"
 
+#include "../glib-compat-private.h"
+
 typedef struct _GstRtspClientSinkPad GstRtspClientSinkPad;
 typedef GstGhostPadClass GstRtspClientSinkPadClass;
 
@@ -301,7 +303,7 @@ gst_rtsp_client_sink_ntp_time_source_get_type (void)
 #define DEFAULT_TLS_DATABASE     NULL
 #define DEFAULT_TLS_INTERACTION     NULL
 #define DEFAULT_NTP_TIME_SOURCE  NTP_TIME_SOURCE_NTP
-#define DEFAULT_USER_AGENT       "GStreamer/" PACKAGE_VERSION
+#define DEFAULT_USER_AGENT       "GStreamer/{VERSION}"
 #define DEFAULT_PROFILES         GST_RTSP_PROFILE_AVP
 #define DEFAULT_RTX_TIME_MS      500
 #define DEFAULT_PUBLISH_CLOCK_MODE GST_RTSP_PUBLISH_CLOCK_MODE_CLOCK
@@ -2166,9 +2168,13 @@ gst_rtsp_client_sink_init_request (GstRTSPClientSink * sink,
     return res;
 
   /* set user-agent */
-  if (sink->user_agent)
-    gst_rtsp_message_add_header (msg, GST_RTSP_HDR_USER_AGENT,
-        sink->user_agent);
+  if (sink->user_agent) {
+    GString *user_agent = g_string_new (sink->user_agent);
+
+    g_string_replace (user_agent, "{VERSION}", PACKAGE_VERSION, 0);
+    gst_rtsp_message_add_header (msg, GST_RTSP_HDR_USER_AGENT, user_agent->str);
+    g_string_free (user_agent, TRUE);
+  }
 
   return res;
 }