feat: expose foreground cwd in pane info

refs #345

8 files changed, 86 insertions, 0 deletions

diff --git a/src/api/schema.rs b/src/api/schema.rs
index cd82f99f..5d933af9 100644
--- a/src/api/schema.rs
+++ b/src/api/schema.rs
@@ -811,6 +811,8 @@ pub struct AgentInfo {
     pub focused: bool,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub cwd: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub foreground_cwd: Option<String>,
     pub revision: u64,
 }
 
@@ -824,6 +826,8 @@ pub struct PaneInfo {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub cwd: Option<String>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub foreground_cwd: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
     pub label: Option<String>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub agent: Option<String>,
@@ -1407,6 +1411,7 @@ mod tests {
                     tab_id: "w_1:1".into(),
                     focused: true,
                     cwd: Some("/worktrees/herdr/worktree-api".into()),
+                    foreground_cwd: None,
                     label: None,
                     agent: None,
                     title: None,
@@ -1457,6 +1462,7 @@ mod tests {
                     tab_id: "w_1:2".into(),
                     focused: false,
                     cwd: Some("/tmp/review".into()),
+                    foreground_cwd: None,
                     label: None,
                     agent: None,
                     title: None,
diff --git a/src/app/agents.rs b/src/app/agents.rs
index 55ee15df..6d463b28 100644
--- a/src/app/agents.rs
+++ b/src/app/agents.rs
@@ -423,6 +423,7 @@ impl App {
             pane_id: pane.pane_id,
             focused: pane.focused,
             cwd: pane.cwd,
+            foreground_cwd: pane.foreground_cwd,
             revision: pane.revision,
         })
     }
diff --git a/src/app/creation.rs b/src/app/creation.rs
index d483eb1a..0f63d60d 100644
--- a/src/app/creation.rs
+++ b/src/app/creation.rs
@@ -288,6 +288,9 @@ impl App {
             cwd: ws.tabs[tab_idx]
                 .cwd_for_pane(pane_id, &self.state.terminals, &self.terminal_runtimes)
                 .map(|cwd| cwd.display().to_string()),
+            foreground_cwd: ws.tabs[tab_idx]
+                .foreground_cwd_for_pane(pane_id, &self.terminal_runtimes)
+                .map(|cwd| cwd.display().to_string()),
             label: terminal.manual_label.clone(),
             agent: terminal.effective_agent_label().map(str::to_string),
             title: presentation.title,
diff --git a/src/pane.rs b/src/pane.rs
index 41bb439c..885fb11d 100644
--- a/src/pane.rs
+++ b/src/pane.rs
@@ -124,6 +124,29 @@ fn should_clear_agent_for_foreground_shell(
     previous_agent.is_some() && new_agent.is_none() && foreground_is_pane_shell
 }
 
+fn usable_process_cwd(pid: u32) -> Option<std::path::PathBuf> {
+    crate::platform::process_cwd(pid).filter(|cwd| cwd.is_absolute() && cwd.is_dir())
+}
+
+fn foreground_member_cwd_different_from_shell(
+    shell_pid: u32,
+    shell_cwd: Option<&std::path::PathBuf>,
+) -> Option<std::path::PathBuf> {
+    let job = crate::detect::foreground_job(shell_pid)?;
+    for process in job.processes {
+        if process.pid == shell_pid {
+            continue;
+        }
+        let Some(cwd) = usable_process_cwd(process.pid) else {
+            continue;
+        };
+        if shell_cwd != Some(&cwd) {
+            return Some(cwd);
+        }
+    }
+    None
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 enum ForegroundShellAgentAction {
     ObserveProbe,
@@ -2111,6 +2134,32 @@ impl PaneRuntime {
         let pid = self.child_pid.load(Ordering::Relaxed);
         crate::platform::process_cwd(pid)
     }
+
+    /// Get the current working directory of the process group controlling the pane PTY.
+    pub fn foreground_cwd(&self) -> Option<std::path::PathBuf> {
+        #[cfg(unix)]
+        {
+            let pid = self.child_pid.load(Ordering::Acquire);
+            let shell_cwd = usable_process_cwd(pid);
+            let foreground_pgid = self
+                .master_fd()
+                .and_then(crate::platform::foreground_process_group_id_for_tty_fd)
+                .or_else(|| crate::platform::foreground_process_group_id(pid));
+            let leader_cwd = foreground_pgid.and_then(usable_process_cwd);
+
+            if leader_cwd.as_ref() == shell_cwd.as_ref() {
+                foreground_member_cwd_different_from_shell(pid, shell_cwd.as_ref()).or(leader_cwd)
+            } else {
+                leader_cwd
+                    .or_else(|| foreground_member_cwd_different_from_shell(pid, shell_cwd.as_ref()))
+            }
+        }
+
+        #[cfg(not(unix))]
+        {
+            None
+        }
+    }
 }
 
 #[cfg(test)]
diff --git a/src/platform/linux.rs b/src/platform/linux.rs
index 046e72c7..d1ae07f1 100644
--- a/src/platform/linux.rs
+++ b/src/platform/linux.rs
@@ -1,5 +1,6 @@
 use std::{
     io::Write,
+    os::fd::RawFd,
     path::PathBuf,
     process::{Command, Stdio},
 };
@@ -86,6 +87,11 @@ pub fn foreground_process_group_id(child_pid: u32) -> Option<u32> {
     (tpgid > 0).then_some(tpgid as u32)
 }
 
+pub fn foreground_process_group_id_for_tty_fd(fd: RawFd) -> Option<u32> {
+    let pgid = unsafe { libc::tcgetpgrp(fd) };
+    (pgid > 0).then_some(pgid as u32)
+}
+
 fn process_pgrp_and_comm(pid: u32) -> Option<(i32, String)> {
     let stat = std::fs::read_to_string(format!("/proc/{pid}/stat")).ok()?;
     let close = stat.rfind(')')?;
diff --git a/src/platform/macos.rs b/src/platform/macos.rs
index ac0e160b..e38b29eb 100644
--- a/src/platform/macos.rs
+++ b/src/platform/macos.rs
@@ -1,5 +1,6 @@
 use std::ffi::OsStr;
 use std::io::Write;
+use std::os::fd::RawFd;
 use std::os::unix::ffi::OsStrExt;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
@@ -177,6 +178,11 @@ pub fn foreground_process_group_id(pid: u32) -> Option<u32> {
     }
 }
 
+pub fn foreground_process_group_id_for_tty_fd(fd: RawFd) -> Option<u32> {
+    let pgid = unsafe { libc::tcgetpgrp(fd) };
+    (pgid > 0).then_some(pgid as u32)
+}
+
 /// Get the effective process name from `argv[0]` via `sysctl(KERN_PROCARGS2)`.
 ///
 /// This is the macOS equivalent of reading `/proc/{pid}/cmdline` on Linux.
diff --git a/src/terminal/runtime.rs b/src/terminal/runtime.rs
index 636972a1..b1a25ee9 100644
--- a/src/terminal/runtime.rs
+++ b/src/terminal/runtime.rs
@@ -373,6 +373,10 @@ impl TerminalRuntime {
         self.0.cwd()
     }
 
+    pub fn foreground_cwd(&self) -> Option<std::path::PathBuf> {
+        self.0.foreground_cwd()
+    }
+
     pub(crate) fn current_size(&self) -> (u16, u16) {
         self.0.current_size()
     }
diff --git a/src/workspace/tab.rs b/src/workspace/tab.rs
index d5ebe00f..100e67d0 100644
--- a/src/workspace/tab.rs
+++ b/src/workspace/tab.rs
@@ -405,4 +405,15 @@ impl Tab {
                     .map(|terminal| terminal.cwd.clone())
             })
     }
+
+    pub fn foreground_cwd_for_pane(
+        &self,
+        pane_id: PaneId,
+        terminal_runtimes: &TerminalRuntimeRegistry,
+    ) -> Option<PathBuf> {
+        let terminal_id = self.terminal_id(pane_id)?;
+        terminal_runtimes
+            .get(terminal_id)
+            .and_then(|rt| rt.foreground_cwd())
+    }
 }