Append = to long options requiring an argument

Make it obvious that the option expects an argument by appending
the equal sign on completion. Suspend space in this case. The
regular expression in `output-options.sh` is adjusted to take into
account this on processing option strings.

shell-completion/hledger-completion.bash.m4

@@ -52,6 +52,11 @@ _hledger_completion_function() {
             # Replace dashes with underscores and use indirect expansion
             subcommandOptions=_hledger_complist_options_${subcommand//-/_}
             _hledger_compreply "$(_hledger_compgen "${!subcommandOptions}")"
+
+            # Suspend space on completion of long options requiring an argument
+            [[ ${COMPREPLY[0]} == --*= ]] && compopt -o nospace
+            compopt +o filenames
+
             return 0
         fi
         break
@@ -64,6 +69,9 @@ _hledger_completion_function() {
         compopt +o filenames
         if [[ $cur == -* ]]; then
             _hledger_compreply "$(_hledger_compgen "$_hledger_complist_generic_options")"
+
+            # Suspend space on completion of long options requiring an argument
+            [[ ${COMPREPLY[0]} == --*= ]] && compopt -o nospace
         else
             _hledger_compreply "$(_hledger_compgen "$_hledger_complist_commands")"
         fi

shell-completion/output-options.sh

@@ -17,7 +17,7 @@ main() {
 
     # Do not print '=' after long options with arg because it makes completion
     # for option arguments harder.
-    sed -rn 's/.* (--[a-zA-Z][-_a-zA-Z0-9]*)=?.*/\1/gp' < "$tmp"
+    sed -rn 's/.* (--[a-zA-Z][-_a-zA-Z0-9]*=?).*/\1/gp' < "$tmp"
 }
 
 main "$@"