Only show global options in the top-level help output.

- Fixes #202.

build.rs

@@ -23,7 +23,7 @@ fn main() {
     subplot_build::codegen("sq.subplot")
         .expect("failed to generate code with Subplot");
 
-    let mut sq = cli::build();
+    let mut sq = cli::build(false);
     generate_shell_completions(&mut sq).unwrap();
     generate_man_pages(&sq).unwrap();
 }

src/cli/mod.rs

@@ -125,7 +125,12 @@ pub const THIRD_PARTY_CERTIFICATION_VALIDITY_DURATION: Duration = Duration::new(
 
 pub const GLOBAL_OPTIONS_HEADER: &str = "Global Options";
 
-pub fn build() -> Command {
+/// Builds the top-level Clap command.
+///
+/// If `globals_hidden` is true, then top-level, global arguments are
+/// marked as hidden, which means they won't be displayed in the help
+/// output.
+pub fn build(globals_hidden: bool) -> Command {
     let sq_version = Box::leak(
         format!(
             "{} (sequoia-openpgp {}, using {})",
@@ -135,7 +140,20 @@ pub fn build() -> Command {
         )
         .into_boxed_str(),
     ) as &str;
-    SqCommand::command().version(sq_version)
+
+    let mut command = SqCommand::command().version(sq_version);
+
+    // Change the globals to be hidden.
+    if globals_hidden {
+        command = command.mut_args(|mut a| {
+            if a.is_global_set() {
+                a = a.hide(globals_hidden);
+            }
+            a
+        });
+    };
+
+    command
 }
 
 /// Defines the CLI.

src/sq.rs

@@ -1053,7 +1053,57 @@ impl<'store> Config<'store> {
 // TODO: Use `derive`d command structs. No more values_of
 // TODO: Handling (and cli position) of global arguments
 fn main() -> Result<()> {
-    let c = cli::SqCommand::from_arg_matches(&cli::build().get_matches())?;
+    let mut cli = cli::build(true);
+    let matches = cli.clone().try_get_matches();
+    let c = match matches {
+        Ok(matches) => {
+            cli::SqCommand::from_arg_matches(&matches)?
+        }
+        Err(err) => {
+            // Warning: hack ahead!
+            //
+            // If we are showing the help output, we only want to
+            // display the global options at the top-level; for
+            // subcommands we hide the global options to not overwhelm
+            // the user.
+            //
+            // Ideally, clap would provide a mechanism to only show
+            // the help output for global options at the level they
+            // are defined at.  That's not the case.
+            //
+            // We can use `err` to figure out if we are showing the
+            // help output, but it doesn't tell us what subcommand we
+            // are showing the help for.  Instead (and here's the
+            // hack!), we compare the output.  If it is the output for
+            // the top-level `--help` or `-h`, then we are showing the
+            // help for the top-level.  If not, then we are showing
+            // the help for a subcommand.  In the former case, we
+            // unhide the global options.
+            use clap::error::ErrorKind;
+            if err.kind() == ErrorKind::DisplayHelp
+                || err.kind() == ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand
+            {
+                let output = err.render();
+                let output = if output == cli.render_long_help() {
+                    Some(cli::build(false).render_long_help())
+                } else if output == cli.render_help() {
+                    Some(cli::build(false).render_help())
+                } else {
+                    None
+                };
+
+                if let Some(output) = output {
+                    if err.use_stderr() {
+                        eprint!("{}", output);
+                    } else {
+                        print!("{}", output);
+                    }
+                    std::process::exit(err.exit_code());
+                }
+            }
+            err.exit();
+        }
+    };
 
     let time: SystemTime =
         c.time.clone().unwrap_or_else(|| Time::now()).into();