From 2c3eb11317972ba5fa87e717cf14e8eb1dfc83c7 Mon Sep 17 00:00:00 2001
From: Magrathean UK <magrathean-uk@users.noreply.github.com>
Date: Sat, 1 Aug 2026 12:05:22 +0100
Subject: [PATCH] fix: check cold data for hot and cold repositories (#1811)

---
 src/commands/check.rs   | 42 +++++++++++++++++++++++++++------
 tests/check_hot_cold.rs | 51 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 7 deletions(-)
 create mode 100644 tests/check_hot_cold.rs

diff --git a/src/commands/check.rs b/src/commands/check.rs
index 4c7460a45..6077ce8c2 100644
--- a/src/commands/check.rs
+++ b/src/commands/check.rs
@@ -8,7 +8,7 @@ use crate::{
 
 use abscissa_core::{Command, Runnable, Shutdown};
 use anyhow::Result;
-use rustic_core::{CheckOptions, repofile::SnapshotFile};
+use rustic_core::{CheckOptions, Credentials, repofile::SnapshotFile};
 
 /// `check` subcommand
 #[derive(clap::Parser, Command, Debug)]
@@ -26,11 +26,35 @@ pub(crate) struct CheckCmd {
 
 impl Runnable for CheckCmd {
     fn run(&self) {
-        if let Err(err) = RUSTIC_APP
-            .config()
-            .repository
-            .run_open(|repo| self.inner_run(repo))
-        {
+        let config = RUSTIC_APP.config();
+        let repository = &config.repository;
+
+        // A hot repository intentionally contains only metadata and tree packs;
+        // data packs live in the cold repository. First preserve the usual
+        // hot/cold consistency checks without reading data. Then create an
+        // isolated cold-only repository for the pack-data check. Reuse the
+        // validated master key so an interactive user is not prompted twice.
+        let result = if self.opts.read_data && repository.be.repo_hot.is_some() {
+            let mut cold_repository = repository.clone();
+            cold_repository.be.repo_hot = None;
+            repository.run(|repo| {
+                let repo = repo.open(&repository.credential_opts)?;
+                let credentials = Credentials::Masterkey(repo.key());
+                let mut metadata_opts = self.opts;
+                metadata_opts.read_data = false;
+                self.inner_run_with_options(repo, metadata_opts)?;
+
+                let cold_repo = cold_repository
+                    .repository(config.global.progress_options)?
+                    .0
+                    .open(&credentials)?;
+                self.inner_run(cold_repo)
+            })
+        } else {
+            repository.run_open(|repo| self.inner_run(repo))
+        };
+
+        if let Err(err) = result {
             status_err!("{}", err);
             RUSTIC_APP.shutdown(Shutdown::Crash);
         };
@@ -39,9 +63,13 @@ impl Runnable for CheckCmd {
 
 impl CheckCmd {
     fn inner_run(&self, repo: OpenRepo) -> Result<()> {
+        self.inner_run_with_options(repo, self.opts)
+    }
+
+    fn inner_run_with_options(&self, repo: OpenRepo, opts: CheckOptions) -> Result<()> {
         let snaps: Vec<SnapshotFile> = get_global_grouped_snapshots(&repo, &self.ids)?.into();
         let trees = snaps.into_iter().map(|snap| snap.tree).collect();
-        repo.check_with_trees(self.opts, trees)?.is_ok()?;
+        repo.check_with_trees(opts, trees)?.is_ok()?;
         Ok(())
     }
 }
diff --git a/tests/check_hot_cold.rs b/tests/check_hot_cold.rs
new file mode 100644
index 000000000..495925c84
--- /dev/null
+++ b/tests/check_hot_cold.rs
@@ -0,0 +1,51 @@
+use std::path::Path;
+
+use assert_cmd::Command;
+use rustic_testing::TestResult;
+use tempfile::tempdir;
+
+fn rustic_runner(profile: &Path, cold_repo: &Path, hot_repo: &Path) -> TestResult<Command> {
+    let mut runner = Command::new(env!("CARGO_BIN_EXE_rustic"));
+    runner
+        .arg("--use-profile")
+        .arg(profile)
+        .arg("--repository")
+        .arg(cold_repo)
+        .arg("--repo-hot")
+        .arg(hot_repo)
+        .args(["--password", "test", "--no-progress", "--no-cache"]);
+    Ok(runner)
+}
+
+#[test]
+fn check_read_data_uses_cold_data_packs_for_hot_cold_repositories() -> TestResult<()> {
+    let temp_dir = tempdir()?;
+    let cold_repo = temp_dir.path().join("cold-repository");
+    let hot_repo = temp_dir.path().join("hot-repository");
+    let source = temp_dir.path().join("source");
+    let profile = temp_dir.path().join("test.toml");
+    std::fs::write(&profile, "")?;
+    std::fs::create_dir(&source)?;
+    std::fs::write(source.join("payload.bin"), vec![42_u8; 256 * 1024])?;
+
+    rustic_runner(&profile, &cold_repo, &hot_repo)?
+        .arg("init")
+        .assert()
+        .success();
+
+    rustic_runner(&profile, &cold_repo, &hot_repo)?
+        .arg("backup")
+        .arg(&source)
+        .assert()
+        .success();
+
+    // Data packs are intentionally stored only in the cold repository. A
+    // successful read-data check proves it reads them there rather than trying
+    // the hot metadata repository.
+    rustic_runner(&profile, &cold_repo, &hot_repo)?
+        .args(["check", "--read-data"])
+        .assert()
+        .success();
+
+    Ok(())
+}