Fix a seriously bad interaction between .git caching and repo cloning

Testcase 2 exhibits a problem with caching the location of .git while
cloning a repository.  Since basedir.get() is called before the clone is
built, a value may get stored in the cache if we are within a
git-controlled tree already.  Then when constructing the object for the
clone, a bogus .git is used, which can lead, when running tests in t/trash,
to corruption of the stgit .git repository.

Testcase 1 does not show any problem by chance, because since we have a
./.git prepared for use by the testsuite, value ".git" get cached, and it
happens that this value will be still valid after chdir'ing into the
newborn clone.

Clearing the cache at the appropriate place fixes the problem.

Signed-off-by: Yann Dirson <ydirson@altern.org>

diff --git a/stgit/basedir.py b/stgit/basedir.py
index c394572a81d9b3322a7a7cdccec0c1846d445dcc..81f2b40ff0da4ac754a7977f01aab92f652a6172 100644 (file)
--- a/stgit/basedir.py
+++ b/stgit/basedir.py
@@ -42,3 +42,9 @@ def get():
             __base_dir = __output('git-rev-parse --git-dir 2> /dev/null')
 
     return __base_dir
+
+def clear_cache():
+    """Clear the cached location of .git
+    """
+    global __base_dir
+    __base_dir = None

diff --git a/stgit/commands/clone.py b/stgit/commands/clone.py
index 9ad76a69710ac0c9379394a64790813f5e3361c8..455dd6eab051ef772ad605a1ad395787c7f621c8 100644 (file)
--- a/stgit/commands/clone.py
+++ b/stgit/commands/clone.py
@@ -51,6 +51,9 @@ def func(parser, options, args):
     os.chdir(local_dir)
     git.checkout(tree_id = 'HEAD')
 
+    # be sure to forget any cached value for .git, since we're going
+    # to work on a brand new repository
+    basedir.clear_cache()
     stack.Series().init()
 
     print 'done'

diff --git a/t/t1100-clone-under.sh b/t/t1100-clone-under.sh
new file mode 100755 (executable)
index 0000000..c86ef61
--- /dev/null
+++ b/t/t1100-clone-under.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Yann Dirson
+#
+
+test_description='Check cloning in a repo subdir
+
+Check that "stg clone" works in a subdir of a git tree.
+This ensures (to some point) that a clone within a tree does
+not corrupt the enclosing repo.
+
+This test must be run before any tests making use of clone.
+'
+
+. ./test-lib.sh
+
+# Here we are in a repo, we have a ./.git
+# Do not get rid of it, or a bug may bite out stgit repo hard
+
+# Need a repo to clone
+test_create_repo foo
+
+test_expect_success \
+    'stg clone right inside a git tree' \
+    "stg clone foo bar"
+
+# now work in a subdir
+mkdir sub
+mv foo sub
+cd sub
+
+test_expect_success \
+    'stg clone deeper under a git tree' \
+    "stg clone foo bar"
+
+test_done