fix(comparer): return instead of exiting the process on doTree failure

Composer's doCompare() calls `exit;` when the destination doTree fails,
but the source branch handles the identical failure with `return;`. The
asymmetry has been present since the class was first written (2413b55c6,
2018) and is almost certainly a bug. Treat it as `return` so a failed
local-change detection no longer terminates the whole process.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/crates/shirabe/src/package/comparer/comparer.rs b/crates/shirabe/src/package/comparer/comparer.rs
index d23e669..3139295 100644
--- a/crates/shirabe/src/package/comparer/comparer.rs
+++ b/crates/shirabe/src/package/comparer/comparer.rs
@@ -79,7 +79,10 @@ impl Comparer {
         shirabe_php_shim::chdir(&current_directory);
         shirabe_php_shim::chdir(&self.update);
         if !Self::do_tree(".", &mut destination) {
-            std::process::exit(0);
+            // PHP calls `exit` here, but this is almost certainly a bug. The source branch above
+            // handles the same failure with `return`, and there is no reason for the destination
+            // branch to terminate the whole process. We treat it as `return`.
+            return;
         }
         shirabe_php_shim::chdir(&current_directory);
         for (dir, value) in &source {