Render more Android functions safe to execute in a batch session

* src/androidfns.c (Fx_display_mm_width, Fx_display_mm_height)
(Fandroid_display_monitor_attributes_list)
(Fandroid_external_storage_available_p)
(Fandroid_request_storage_access): Verify that a display
connection or service object is available.

* src/androidselect.c (Fandroid_get_clipboard)
(Fandroid_browse_url_internal, Fandroid_get_clipboard_targets)
(Fandroid_get_clipboard_data, Fandroid_notifications_notify):
Moderate tone of error messages.

2 files changed, 16 insertions, 5 deletions

diff --git a/src/androidfns.c b/src/androidfns.c
index 7595e176618..af2247ad962 100644
--- a/src/androidfns.c
+++ b/src/androidfns.c
@@ -1374,6 +1374,7 @@ DEFUN ("x-display-mm-width", Fx_display_mm_width, Sx_display_mm_width,
   error ("Android cross-compilation stub called!");
   return Qnil;
 #else
+  check_android_display_info (terminal);
   return make_fixnum (android_get_mm_width ());
 #endif
 }
@@ -1386,6 +1387,7 @@ DEFUN ("x-display-mm-height", Fx_display_mm_height, Sx_display_mm_height,
   error ("Android cross-compilation stub called!");
   return Qnil;
 #else
+  check_android_display_info (terminal);
   return make_fixnum (android_get_mm_height ());
 #endif
 }
@@ -1469,6 +1471,7 @@ Internal use only, use `display-monitor-attributes-list' instead.  */)
 #else
   struct MonitorInfo monitor;
 
+  check_android_display_info (terminal);
   memset (&monitor, 0, sizeof monitor);
   monitor.geom.width = android_get_screen_width ();
   monitor.geom.height = android_get_screen_height ();
@@ -3270,6 +3273,11 @@ External storage on Android encompasses the `/sdcard' and
 absent these permissions.  */)
   (void)
 {
+  /* Implement a rather undependable fallback when no GUI is
+     available.  */
+  if (!android_init_gui)
+    return Ffile_accessible_directory_p (build_string ("/sdcard"));
+
   return android_external_storage_available_p () ? Qt : Qnil;
 }
 
@@ -3284,6 +3292,9 @@ Use `android-external-storage-available-p' (which see) to verify
 whether Emacs has actually received such access permissions.  */)
   (void)
 {
+  if (!android_init_gui)
+    return Qnil;
+
   android_request_storage_access ();
   return Qnil;
 }
diff --git a/src/androidselect.c b/src/androidselect.c
index d5783b75417..cbd163c6c9f 100644
--- a/src/androidselect.c
+++ b/src/androidselect.c
@@ -189,7 +189,7 @@ Alternatively, return nil if the clipboard is empty.  */)
   const char *data;
 
   if (!android_init_gui)
-    error ("No Android display connection!");
+    error ("No Android display connection");
 
   method = clipboard_class.get_clipboard;
   text
@@ -258,7 +258,7 @@ for.  Use `android-browse-url' instead.  */)
   Lisp_Object value;
 
   if (!android_init_gui)
-    error ("No Android display connection!");
+    error ("No Android display connection");
 
   CHECK_STRING (url);
   value = android_browse_url (url, send);
@@ -290,7 +290,7 @@ data type available from the clipboard.  */)
   Lisp_Object targets, tem;
 
   if (!android_init_gui)
-    error ("No Android display connection!");
+    error ("No Android display connection");
 
   targets = Qnil;
   block_input ();
@@ -544,7 +544,7 @@ does not have any corresponding data.  In that case, use
   char *buffer, *start;
 
   if (!android_init_gui)
-    error ("No Android display connection!");
+    error ("No Android display connection");
 
   CHECK_STRING (type);
 
@@ -1003,7 +1003,7 @@ usage: (android-notifications-notify &rest ARGS) */)
   AUTO_STRING (default_icon, "ic_dialog_alert");
 
   if (!android_init_gui)
-    error ("No Android display connection!");
+    error ("No Android display connection");
 
   /* Clear each variable above.  */
   title = body = replaces_id = group = icon = urgency = actions = Qnil;