Add hexadecimal support to --embed

Closes #6145.

5 files changed, 33 insertions, 5 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 507f3ccc..8591416e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Escape sequence to set underline color (`CSI 58 : 2 : Ps : Ps : Ps m`/`CSI 58 : 5 : Ps m`)
 - Escape sequence to reset underline color (`CSI 59 m`)
 - Vi mode keybinding (z) to center view around vi mode cursor
+- Accept hexadecimal values starting with `0x` for `--embed`
 
 ### Changed
 
diff --git a/alacritty/src/cli.rs b/alacritty/src/cli.rs
index be377700..8872ec99 100644
--- a/alacritty/src/cli.rs
+++ b/alacritty/src/cli.rs
@@ -1,4 +1,5 @@
 use std::cmp::max;
+use std::os::raw::c_ulong;
 use std::path::PathBuf;
 
 #[cfg(unix)]
@@ -25,7 +26,7 @@ pub struct Options {
     #[clap(long)]
     pub ref_test: bool,
 
-    /// Defines the X11 window ID (as a decimal integer) to embed Alacritty within.
+    /// X11 window ID to embed Alacritty within (decimal or hexadecimal with "0x" prefix).
     #[clap(long)]
     pub embed: Option<String>,
 
@@ -100,7 +101,7 @@ impl Options {
         }
 
         config.window.dynamic_title &= self.window_options.window_identity.title.is_none();
-        config.window.embed = self.embed.as_ref().and_then(|embed| embed.parse().ok());
+        config.window.embed = self.embed.as_ref().and_then(|embed| parse_hex_or_decimal(embed));
         config.debug.print_events |= self.print_events;
         config.debug.log_level = max(config.debug.log_level, self.log_level());
         config.debug.ref_test |= self.ref_test;
@@ -173,6 +174,14 @@ fn parse_class(input: &str) -> Result<Class, String> {
     }
 }
 
+/// Convert to hex if possible, else decimal
+fn parse_hex_or_decimal(input: &str) -> Option<c_ulong> {
+    input
+        .strip_prefix("0x")
+        .and_then(|value| c_ulong::from_str_radix(value, 16).ok())
+        .or_else(|| input.parse().ok())
+}
+
 /// Terminal specific cli options which can be passed to new windows via IPC.
 #[derive(Serialize, Deserialize, Args, Default, Debug, Clone, PartialEq, Eq)]
 pub struct TerminalOptions {
@@ -393,6 +402,24 @@ mod tests {
         assert!(class.is_err());
     }
 
+    #[test]
+    fn valid_decimal() {
+        let value = parse_hex_or_decimal("10485773");
+        assert_eq!(value, Some(10485773));
+    }
+
+    #[test]
+    fn valid_hex_to_decimal() {
+        let value = parse_hex_or_decimal("0xa0000d");
+        assert_eq!(value, Some(10485773));
+    }
+
+    #[test]
+    fn invalid_hex_to_decimal() {
+        let value = parse_hex_or_decimal("0xa0xx0d");
+        assert_eq!(value, None);
+    }
+
     #[cfg(target_os = "linux")]
     #[test]
     fn completions() {
diff --git a/extra/alacritty.man b/extra/alacritty.man
index 1ac63f04..eec20d60 100644
--- a/extra/alacritty.man
+++ b/extra/alacritty.man
@@ -52,7 +52,7 @@ Alacritty looks for the configuration file at the following paths:
 On Windows, the configuration file is located at %APPDATA%\\alacritty\\alacritty.yml.
 .TP
 \fB\-\-embed\fR <parent>
-Defines the X11 window ID (as a decimal integer) to embed Alacritty within
+X11 window ID to embed Alacritty within (decimal or hexadecimal with "0x" prefix)
 .TP
 \fB\-o\fR, \fB\-\-option\fR <option>...
 Override configuration file options [example: cursor.style=Beam]
diff --git a/extra/completions/_alacritty b/extra/completions/_alacritty
index 86226236..50a5c00d 100644
--- a/extra/completions/_alacritty
+++ b/extra/completions/_alacritty
@@ -15,7 +15,7 @@ _alacritty() {
 
     local context curcontext="$curcontext" state line
     _arguments "${_arguments_options[@]}" \
-'--embed=[Defines the X11 window ID (as a decimal integer) to embed Alacritty within]:EMBED: ' \
+'--embed=[X11 window ID to embed Alacritty within (decimal or hexadecimal with "0x" prefix)]:EMBED: ' \
 '--config-file=[Specify alternative configuration file \[default: $XDG_CONFIG_HOME/alacritty/alacritty.yml\]]:CONFIG_FILE:_files' \
 '--socket=[Path for IPC socket creation]:SOCKET:_files' \
 '*-o+[Override configuration file options \[example: cursor.style=Beam\]]:OPTION: ' \
diff --git a/extra/completions/alacritty.fish b/extra/completions/alacritty.fish
index f425448b..69b3d777 100644
--- a/extra/completions/alacritty.fish
+++ b/extra/completions/alacritty.fish
@@ -1,4 +1,4 @@
-complete -c alacritty -n "__fish_use_subcommand" -l embed -d 'Defines the X11 window ID (as a decimal integer) to embed Alacritty within' -r
+complete -c alacritty -n "__fish_use_subcommand" -l embed -d 'X11 window ID to embed Alacritty within (decimal or hexadecimal with "0x" prefix)' -r
 complete -c alacritty -n "__fish_use_subcommand" -l config-file -d 'Specify alternative configuration file [default: $XDG_CONFIG_HOME/alacritty/alacritty.yml]' -r -F
 complete -c alacritty -n "__fish_use_subcommand" -l socket -d 'Path for IPC socket creation' -r -F
 complete -c alacritty -n "__fish_use_subcommand" -s o -l option -d 'Override configuration file options [example: cursor.style=Beam]' -r