Refactor try-finally cleanup in git/

This is, in part, to help avoid (or be able to notice) other bugs
like the rollback bug that affected SymbolicReference. However, it
also includes a simplification of try-(try-except)-finally to
try-except-finally.

Author: EliahKagan

git/config.py

@@ -406,15 +406,14 @@ def release(self) -> None:
             return
 
         try:
-            try:
-                self.write()
-            except IOError:
-                log.error("Exception during destruction of GitConfigParser", exc_info=True)
-            except ReferenceError:
-                # This happens in PY3 ... and usually means that some state cannot be written
-                # as the sections dict cannot be iterated
-                # Usually when shutting down the interpreter, don'y know how to fix this
-                pass
+            self.write()
+        except IOError:
+            log.error("Exception during destruction of GitConfigParser", exc_info=True)
+        except ReferenceError:
+            # This happens in PY3 ... and usually means that some state cannot be
+            # written as the sections dict cannot be iterated
+            # Usually when shutting down the interpreter, don't know how to fix this
+            pass
         finally:
             if self._lock is not None:
                 self._lock._release_lock()

git/index/base.py

@@ -224,13 +224,11 @@ def write(
         lfd = LockedFD(file_path or self._file_path)
         stream = lfd.open(write=True, stream=True)
 
-        ok = False
         try:
             self._serialize(stream, ignore_extension_data)
-            ok = True
-        finally:
-            if not ok:
-                lfd.rollback()
+        except BaseException:
+            lfd.rollback()
+            raise
 
         lfd.commit()
 

git/refs/symbolic.py

@@ -370,14 +370,12 @@ def set_reference(
 
         lfd = LockedFD(fpath)
         fd = lfd.open(write=True, stream=True)
-        ok = False
         try:
             fd.write(write_value.encode("utf-8") + b"\n")
             lfd.commit()
-            ok = True
-        finally:
-            if not ok:
-                lfd.rollback()
+        except BaseException:
+            lfd.rollback()
+            raise
         # Adjust the reflog
         if logmsg is not None:
             self.log_append(oldbinsha, logmsg)