Remove terminfo dependency

Fixes #4597.

Co-authored-by: Christian Duerr <contact@christianduerr.com>

3 files changed, 50 insertions, 75 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f9b53890..a520832a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -75,6 +75,7 @@ dependencies = [
  "alacritty_config_derive",
  "base64",
  "bitflags",
+ "dirs",
  "libc",
  "log",
  "mio",
@@ -89,7 +90,6 @@ dependencies = [
  "serde_json",
  "serde_yaml",
  "signal-hook",
- "terminfo",
  "unicode-width",
  "vte",
  "winapi 0.3.9",
@@ -1483,44 +1483,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
 
 [[package]]
-name = "phf"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3dfb61232e34fcb633f43d12c58f83c1df82962dcdfa565a4e866ffc17dafe12"
-dependencies = [
- "phf_shared",
-]
-
-[[package]]
-name = "phf_codegen"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbffee61585b0411840d3ece935cce9cb6321f01c45477d30066498cd5e1a815"
-dependencies = [
- "phf_generator",
- "phf_shared",
-]
-
-[[package]]
-name = "phf_generator"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17367f0cc86f2d25802b2c26ee58a7b23faeccf78a396094c13dced0d0182526"
-dependencies = [
- "phf_shared",
- "rand",
-]
-
-[[package]]
-name = "phf_shared"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c00cf8b9eafe68dde5e9eaa2cef8ee84a9336a47d566ec55ca16589633b65af7"
-dependencies = [
- "siphasher",
-]
-
-[[package]]
 name = "pkg-config"
 version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1587,7 +1549,6 @@ dependencies = [
  "rand_chacha",
  "rand_core",
  "rand_hc",
- "rand_pcg",
 ]
 
 [[package]]
@@ -1619,15 +1580,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "rand_pcg"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16abd0c1b639e9eb4d7c50c0b8100b0d0f849be2349829c740fe8e6eb4816429"
-dependencies = [
- "rand_core",
-]
-
-[[package]]
 name = "raw-window-handle"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1880,12 +1832,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "siphasher"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa8f3741c7372e75519bd9346068370c9cdaabcc1f9599cbcf2a2719352286b7"
-
-[[package]]
 name = "slab"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1992,19 +1938,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "terminfo"
-version = "0.7.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76971977e6121664ec1b960d1313aacfa75642adc93b9d4d53b247bd4cb1747e"
-dependencies = [
- "dirs",
- "fnv",
- "nom",
- "phf",
- "phf_codegen",
-]
-
-[[package]]
 name = "textwrap"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/alacritty_terminal/Cargo.toml b/alacritty_terminal/Cargo.toml
index 9bdccf7b..b859185c 100644
--- a/alacritty_terminal/Cargo.toml
+++ b/alacritty_terminal/Cargo.toml
@@ -24,8 +24,8 @@ mio-extras = "2"
 log = "0.4"
 unicode-width = "0.1"
 base64 = "0.12.0"
-terminfo = "0.7.1"
 regex-automata = "0.1.9"
+dirs = "2.0.2"
 
 [target.'cfg(unix)'.dependencies]
 nix = "0.18.0"
diff --git a/alacritty_terminal/src/tty/mod.rs b/alacritty_terminal/src/tty/mod.rs
index 7df4f140..a1c8c0c1 100644
--- a/alacritty_terminal/src/tty/mod.rs
+++ b/alacritty_terminal/src/tty/mod.rs
@@ -1,9 +1,8 @@
 //! TTY related functionality.
 
+use std::path::PathBuf;
 use std::{env, io};
 
-use terminfo::Database;
-
 use crate::config::Config;
 
 #[cfg(not(windows))]
@@ -65,10 +64,8 @@ pub fn setup_env<C>(config: &Config<C>) {
     // Default to 'alacritty' terminfo if it is available, otherwise
     // default to 'xterm-256color'. May be overridden by user's config
     // below.
-    env::set_var(
-        "TERM",
-        if Database::from_name("alacritty").is_ok() { "alacritty" } else { "xterm-256color" },
-    );
+    let terminfo = if terminfo_exists("alacritty") { "alacritty" } else { "xterm-256color" };
+    env::set_var("TERM", terminfo);
 
     // Advertise 24-bit color support.
     env::set_var("COLORTERM", "truecolor");
@@ -81,3 +78,48 @@ pub fn setup_env<C>(config: &Config<C>) {
         env::set_var(key, value);
     }
 }
+
+/// Check if a terminfo entry exists on the system.
+fn terminfo_exists(terminfo: &str) -> bool {
+    // Get first terminfo character for the parent directory.
+    let first = terminfo.get(..1).unwrap_or_default();
+    let first_hex = format!("{:x}", first.chars().next().unwrap_or_default() as usize);
+
+    // Return true if the terminfo file exists at the specified location.
+    macro_rules! check_path {
+        ($path:expr) => {
+            if $path.join(first).join(terminfo).exists()
+                || $path.join(&first_hex).join(terminfo).exists()
+            {
+                return true;
+            }
+        };
+    }
+
+    if let Some(dir) = env::var_os("TERMINFO") {
+        check_path!(PathBuf::from(&dir));
+    } else if let Some(home) = dirs::home_dir() {
+        check_path!(home.join(".terminfo"));
+    }
+
+    if let Ok(dirs) = env::var("TERMINFO_DIRS") {
+        for dir in dirs.split(':') {
+            check_path!(PathBuf::from(dir));
+        }
+    }
+
+    if let Ok(prefix) = env::var("PREFIX") {
+        let path = PathBuf::from(prefix);
+        check_path!(path.join("etc/terminfo"));
+        check_path!(path.join("lib/terminfo"));
+        check_path!(path.join("share/terminfo"));
+    }
+
+    check_path!(PathBuf::from("/etc/terminfo"));
+    check_path!(PathBuf::from("/lib/terminfo"));
+    check_path!(PathBuf::from("/usr/share/terminfo"));
+    check_path!(PathBuf::from("/boot/system/data/terminfo"));
+
+    // No valid terminfo path has been found.
+    false
+}