Fix ci_in when there is nothing to prepare

ci/release_notes.md

@@ -1 +1,3 @@
-Empty - please add release notes here
+## Improvement
+
+- reproduce last state when there is nothing to prepare in ci_in

src/concourse/ci_in.rs

@@ -56,13 +56,20 @@ pub fn exec(destination: &str) -> Result<()> {
             std::process::exit(1);
         }
         None => {
-            eprintln!("Nothing new to deploy... providing an empty dir");
-            return empty_repo(version);
+            eprintln!("Nothing new to deploy... reproducing last state");
+            let reproduced = ws.reproduce(env, true)?;
+            if &reproduced != wanted_trigger {
+                eprintln!("Reproduced state is out of sync - providing empty dir");
+                return empty_repo(version);
+            }
+            (reproduced, Vec::new())
+        }
+        Some(ret) => {
+            eprintln!("Preparing the workspace");
+            ws.prepare(env, gate, true)?;
+            ret
         }
-        Some(ret) => ret,
     };
-    eprintln!("Preparing the workspace");
-    ws.prepare(env, gate, true)?;
 
     std::fs::write(".git/cepler_environment", &environment)
         .context("Couldn't create file '.git/cepler_environment'")?;

src/workspace.rs

@@ -72,7 +72,7 @@ impl Workspace {
         Ok(Some((new_env_state.head_commit.inner(), diffs)))
     }
 
-    pub fn reproduce(&self, env: &EnvironmentConfig, force_clean: bool) -> Result<()> {
+    pub fn reproduce(&self, env: &EnvironmentConfig, force_clean: bool) -> Result<String> {
         let repo = Repo::open(None)?;
         if let Some(last_state) = self.db.get_current_state(&env.name) {
             if force_clean {
@@ -81,11 +81,12 @@ impl Workspace {
             for (ident, state) in last_state.files.iter() {
                 repo.checkout_file_from(&ident.name(), &state.from_commit)?;
             }
-            Ok(())
+            Ok(last_state.head_commit.clone().inner())
         } else {
             Err(anyhow!("No state recorded for {}", env.name))
         }
     }
+
     pub fn prepare(
         &self,
         env: &EnvironmentConfig,