From 74daa5d3a0cb0702e5f017b694437cfb78b20ba3 Mon Sep 17 00:00:00 2001
From: Preetam Dwivedi <preetam@uber.com>
Date: Wed, 30 Sep 2026 11:08:46 -0700
Subject: [PATCH] Reject zero per-repo concurrency
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## Summary

### Why?

A zero-sized per-repository semaphore can never grant a permit, so a valid-looking configuration caused every Git request for a repository to wait indefinitely.

### What?

Require `server.max_concurrent_per_repo` to be positive and add a regression test for the invalid zero value.

## Test Plan

✅ `cargo test -p walgit-config zero_per_repo_concurrency_is_rejected`
✅ `cargo fmt --all -- --check`
✅ `git diff --check`

## Issue

Closes #79
---
 crates/walgit-config/src/lib.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/crates/walgit-config/src/lib.rs b/crates/walgit-config/src/lib.rs
index b5aca125..0ae1a152 100644
--- a/crates/walgit-config/src/lib.rs
+++ b/crates/walgit-config/src/lib.rs
@@ -1081,6 +1081,10 @@ impl Config {
             self.server.max_concurrent_requests > 0,
             "server.max_concurrent_requests must be positive"
         );
+        anyhow::ensure!(
+            self.server.max_concurrent_per_repo > 0,
+            "server.max_concurrent_per_repo must be positive"
+        );
         anyhow::ensure!(
             !self.server.request_timeout.is_zero(),
             "server.request_timeout must be positive"
@@ -1360,6 +1364,14 @@ mod tests {
         assert_eq!(back.store.bucket, c.store.bucket);
     }
 
+    #[test]
+    fn zero_per_repo_concurrency_is_rejected() {
+        let mut c = Config::default();
+        c.server.max_concurrent_per_repo = 0;
+        let err = c.validate().unwrap_err().to_string();
+        assert!(err.contains("server.max_concurrent_per_repo must be positive"));
+    }
+
     #[test]
     fn example_configurations_parse_and_validate() {
         Config::parse(include_str!("../../../walgit.example.toml")).unwrap();