mu4e: use mu4e-config instead of mu4e-meta

All these changes to avoid:

,----
| mu4e/meson.build:92: WARNING: Source item '/home/djcb/Sources/mu/build/mu4e/mu4e-meta.el' cannot be converted to File object, because it is a generated file. This will become a hard error in the future
`----

This is because we want to byte-compile a file we just before generated using
configure_file. This does not seem like a crazy thing, but meson threatens with
breaking the build at some point in the future.

So instead, we decide _not_ to compile this (very boring) file. But, users may
still have an older mu4e-meta.elc lying around, leading to confusion.

So, let's rename that file and we're golden.

.gitignore

@@ -89,7 +89,7 @@ test-sexp-parser
 test-scanner
 /guile/tests/test-mu-guile
 
-mu4e-meta.el
+mu4e-config.el
 mu4e.pdf
 texinfo.tex
 texi.texi

configure.ac

@@ -257,7 +257,7 @@ lib/utils/Makefile
 lib/message/Makefile
 lib/index/Makefile
 mu4e/Makefile
-mu4e/mu4e-meta.el
+mu4e/mu4e-config.el
 guile/Makefile
 guile/mu/Makefile
 guile/examples/Makefile

mu4e/Makefile.am

@@ -37,7 +37,7 @@ dist_lisp_LISP=			\
 	mu4e-main.el		\
 	mu4e-mark.el		\
 	mu4e-message.el		\
-	mu4e-meta.el		\
+	mu4e-config.el		\
 	mu4e-org.el		\
 	mu4e-search.el		\
 	mu4e-server.el		\

mu4e/meson.build

@@ -14,9 +14,15 @@
 ## along with this program; if not, write to the Free Software Foundation,
 ## Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
+# where the lisp goes
+lispdir =  join_paths(datadir, 'emacs', 'site-lisp', 'mu4e')
+
+# generate some build data for use in mu4e
 mu4e_meta = configure_file(
-  input: 'mu4e-meta.el.in',
-  output: 'mu4e-meta.el',
+  input: 'mu4e-config.el.in',
+  output: 'mu4e-config.el',
+  install: true,
+  install_dir: lispdir,
   configuration: {
       'VERSION'         : meson.project_version(),
       # project_build_root() with meson >= 0.56
@@ -24,7 +30,7 @@ mu4e_meta = configure_file(
       'MU_DOC_DIR'      : join_paths(datadir, 'doc', 'mu'),
     })
 
-mu4e_plain_srcs=[
+mu4e_srcs=[
   'mu4e-actions.el',
   'mu4e-bookmarks.el',
   'mu4e-compose.el',
@@ -51,27 +57,20 @@ mu4e_plain_srcs=[
   'obsolete/org-mu4e.el',
 ]
 
-mu4e_gen_srcs=[
-  join_paths(meson.current_build_dir(), 'mu4e-meta.el'),
-]
-
-mu4e_all_srcs =  mu4e_plain_srcs
-mu4e_all_srcs += mu4e_gen_srcs
+# note, we cannot compile mu4e-config.el without incurring
+#  WARNING: Source item
+#   '[...]/build/mu4e/mu4e-meta.el' cannot be converted to File object, because
+#   it is a generated file. This will become a hard error in the future.
+#
+#... so let's not do that!
 
 # hack-around for native compile issue: copy sources to builddir.
 # see: https://debbugs.gnu.org/db/47/47987.html
-foreach src : mu4e_plain_srcs
+foreach src : mu4e_srcs
   configure_file(input: src, output:'@BASENAME@.el', copy:true)
 endforeach
 
-
-# XXX: this yields a warning: mu4e/meson.build:86: WARNING: Source item
-#   '[...]/build/mu4e/mu4e-meta.el' cannot be converted to File object, because
-#   it is a generated file. This will become a hard error in the future.
-# unsure how to best avoid that.
-
-lispdir =  join_paths(datadir, 'emacs', 'site-lisp', 'mu4e')
-foreach src : mu4e_all_srcs
+foreach src : mu4e_srcs
   target_name= '@BASENAME@.elc'
   target_path = join_paths(meson.current_build_dir(), target_name)
   target_func = '(setq byte-compile-dest-file-function(lambda(_) "' + target_path + '"))'
@@ -92,8 +91,8 @@ foreach src : mu4e_all_srcs
 			  '--funcall', 'batch-byte-compile', '@INPUT@'])
 endforeach
 
-# also install the sources.
-install_data(mu4e_all_srcs, install_dir: lispdir)
+# also install the sources and the config
+install_data(mu4e_srcs, install_dir: lispdir)
 
 # install mu4e-about.org
 install_data('mu4e-about.org', install_dir : join_paths(datadir, 'doc', 'mu'))

mu4e/mu4e-actions.el

@@ -32,7 +32,6 @@
 (require 'mu4e-helpers)
 (require 'mu4e-message)
 (require 'mu4e-search)
-(require 'mu4e-meta)
 
 
 ;;; Count lines

mu4e/mu4e-config.el.in

@@ -1,4 +1,5 @@
 ;; auto-generated
+
 (defconst mu4e-mu-version "@VERSION@"
   "Required mu binary version; mu4e's version must agree with this.")
 
@@ -8,4 +9,4 @@
 (defconst mu4e-doc-dir "@MU_DOC_DIR@"
   "Mu4e's data-dir.")
 
-(provide 'mu4e-meta)
+(provide 'mu4e-config)

mu4e/mu4e-helpers.el

@@ -31,6 +31,7 @@
 (require 'ido)
 (require 'cl-lib)
 
+(require 'mu4e-config)
 
 ;;; Customization
 

mu4e/mu4e-server.el

@@ -25,7 +25,6 @@
 ;;; Code:
 
 (require 'mu4e-helpers)
-(require 'mu4e-meta)
 
 
 ;;; Configuration

mu4e/mu4e-vars.el

@@ -24,7 +24,6 @@
 
 ;;; Code:
 
-(require 'mu4e-meta)
 (require 'message)
 (require 'mu4e-helpers)