Don't restack abandoned or merged changes

Closes #48

Cargo.toml

@@ -33,6 +33,7 @@ serde = { version = "1.0.197", features = ["derive"] }
 serde_json = "1.0.115"
 serde_with = { version = "3.7.0", features = ["time_0_3"] }
 shell-words = "1.1.0"
+tap = "1.0.1"
 time = { version = "0.3.34", features = ["local-offset", "formatting", "macros"] }
 tracing = { version = "0.1.40", features = ["attributes"] }
 tracing-human-layer = "0.1.3"

src/change_number.rs

@@ -6,8 +6,10 @@ use clap::builder::ValueParserFactory;
 use owo_colors::OwoColorize;
 use owo_colors::Stream::Stderr;
 use owo_colors::Style;
+use tap::Pipe;
 
 use crate::change::Change;
+use crate::change_status::ChangeStatus;
 use crate::gerrit::Gerrit;
 use crate::patchset::ChangePatchset;
 use crate::patchset::Patchset;
@@ -47,10 +49,28 @@ impl ChangeNumber {
     }
 
     pub fn pretty(&self, gerrit: &Gerrit) -> miette::Result<String> {
-        let subject = gerrit.get_change(*self)?.subject;
+        let change = gerrit.get_change(*self)?;
+        let subject = change.subject;
+        let abandoned = change.status == ChangeStatus::Abandoned;
+        let merged = change.status == ChangeStatus::Merged;
+        let wip = change.wip;
+        let styled = |style: owo_colors::Style| {
+            if merged {
+                style.magenta()
+            } else if abandoned {
+                style.dimmed().strikethrough()
+            } else if wip {
+                style.dimmed()
+            } else {
+                style.green()
+            }
+        };
         Ok(format!(
             "{}{}",
-            self.if_supports_color(Stderr, |change| Style::new().bold().green().style(change)),
+            self.if_supports_color(Stderr, |change| Style::new()
+                .bold()
+                .pipe(styled)
+                .style(change)),
             subject
                 .map(|subject| format!(" ({subject})"))
                 .unwrap_or_default()

src/restack.rs

@@ -14,6 +14,7 @@ use miette::Context;
 use miette::IntoDiagnostic;
 
 use crate::change_number::ChangeNumber;
+use crate::change_status::ChangeStatus;
 use crate::commit_hash::CommitHash;
 use crate::dependency_graph::DependencyGraph;
 use crate::gerrit::GerritGitRemote;
@@ -308,9 +309,20 @@ pub fn create_todo(gerrit: &mut GerritGitRemote, branch: &str) -> miette::Result
         queue.push_front(*root);
 
         while let Some(change) = queue.pop_back() {
-            if roots.contains(&change) {
+            let change = gerrit.get_change(change)?;
+
+            match change.status {
+                ChangeStatus::New => {
+                    // Carry on.
+                }
+                ChangeStatus::Merged | ChangeStatus::Abandoned => {
+                    tracing::debug!("Skipping merged/abandoned change {}", change.number);
+                    continue;
+                }
+            }
+
+            if roots.contains(&change.number) {
                 // Change is root, cherry-pick on target branch.
-                let change = gerrit.get_change(change)?;
                 let step = Step {
                     change: change.number,
                     onto: RestackOnto::Branch {
@@ -324,18 +336,18 @@ pub fn create_todo(gerrit: &mut GerritGitRemote, branch: &str) -> miette::Result
                 // Change is not root, cherry-pick on parent.
                 let parent = todo
                     .graph
-                    .depends_on(change)
-                    .ok_or_else(|| miette!("Change does not have parent: {change}"))?;
+                    .depends_on(change.number)
+                    .ok_or_else(|| miette!("Change does not have parent: {}", change.number))?;
 
                 let step = Step {
-                    change,
+                    change: change.number,
                     onto: RestackOnto::Change(parent),
                 };
                 tracing::debug!(%step, "Discovered restack step");
                 todo.steps.push_back(step);
             }
 
-            let reverse_dependencies = todo.graph.needed_by(change);
+            let reverse_dependencies = todo.graph.needed_by(change.number);
 
             for needed_by in reverse_dependencies {
                 if !seen.contains(needed_by) {