fix: transaction() releases the pooled connection when begin() fails (lockstep w/ psql-1)

same acquire-then-fail leak as psql: begin() failing after acquire leaked the conn. release
on failure. verified against MariaDB: 6 forced begin-failures no longer drain the pool.
bump v0.1.0 -> v0.1.1

Signed-off-by: disqualifier <dev@disqualifier.me>

README.md

@@ -11,18 +11,18 @@ wire-compatible and share the driver, so this covers both.
 `requirements.txt`:
 
 ```
-mysql @ git+ssh://git@git.rethinkstudios.io/rethink-public/mysql.git@v0.1.0
+mysql @ git+ssh://git@git.rethinkstudios.io/rethink-public/mysql.git@v0.1.1
 ```
 
 Direct:
 
 ```bash
-pip install "mysql @ git+ssh://git@git.rethinkstudios.io/rethink-public/mysql.git@v0.1.0"
+pip install "mysql @ git+ssh://git@git.rethinkstudios.io/rethink-public/mysql.git@v0.1.1"
 ```
 
 Pulls `aiomysql` (which pulls `PyMySQL`).
 
-Drop the `@v0.1.0` suffix from the line above to install the latest unpinned.
+Drop the `@v0.1.1` suffix from the line above to install the latest unpinned.
 
 ## The two-layer API
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "mysql"
-version = "0.1.0"
+version = "0.1.1"
 description = "async mysql/mariadb wrapper over aiomysql: two-layer API (friendly verbs + raw escape hatch), fail-loud, config-free"
 requires-python = ">=3.10"
 dependencies = [

src/mysql/mysql.py

@@ -373,7 +373,15 @@ class _Transaction:
 
     async def __aenter__(self):
         self._conn = await self._pool.acquire()
-        await self._conn.begin()
+        try:
+            await self._conn.begin()
+        except BaseException:
+            # begin() failing after acquire would otherwise leak the pooled connection —
+            # __aexit__ is not called when __aenter__ raises. release it and reset so a
+            # failed transaction start never burns a pool slot.
+            self._pool.release(self._conn)
+            self._conn = None
+            raise
         return self._conn
 
     async def __aexit__(self, exc_type, exc, tb) -> None: