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git/t/t5615-alternate-env.sh

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alternates: re-allow relative paths from environment Commit 670c359da (link_alt_odb_entry: handle normalize_path errors, 2016-10-03) regressed the handling of relative paths in the GIT_ALTERNATE_OBJECT_DIRECTORIES variable. It's not entirely clear this was ever meant to work, but it _has_ worked for several years, so this commit restores the original behavior. When we get a path in GIT_ALTERNATE_OBJECT_DIRECTORIES, we add it the path to the list of alternate object directories as if it were found in objects/info/alternates, but with one difference: we do not provide the link_alt_odb_entry() function with a base for relative paths. That function doesn't turn it into an absolute path, and we end up feeding the relative path to the strbuf_normalize_path() function. Most relative paths break out of the top-level directory (e.g., "../foo.git/objects"), and thus normalizing fails. Prior to 670c359da, we simply ignored the error, and due to the way normalize_path_copy() was implemented it happened to return the original path in this case. We then accessed the alternate objects using this relative path. By storing the relative path in the alt_odb list, the path is relative to wherever we happen to be at the time we do an object lookup. That means we look from $GIT_DIR in a bare repository, and from the top of the worktree in a non-bare repository. If this were being designed from scratch, it would make sense to pick a stable location (probably $GIT_DIR, or even the object directory) and use that as the relative base, turning the result into an absolute path. However, given the history, at this point the minimal fix is to match the pre-670c359da behavior. We can do this simply by ignoring the error when we have no relative base and using the original value (which we now reliably have, thanks to strbuf_normalize_path()). That still leaves us with a relative path that foils our duplicate detection, and may act strangely if we ever chdir() later in the process. We could solve that by storing an absolute path based on getcwd(). That may be a good future direction; for now we'll do just the minimum to fix the regression. The new t5615 script demonstrates the fix in its final three tests. Since we didn't have any tests of the alternates environment variable at all, it also adds some tests of absolute paths. Reported-by: Bryan Turner <bturner@atlassian.com> Signed-off-by: Jeff King <peff@peff.net>
2016-11-08 05:50:17 +01:00
#!/bin/sh
test_description='handling of alternates in environment variables'
. ./test-lib.sh
check_obj () {
alt=$1; shift
while read obj expect
do
echo "$obj" >&3 &&
echo "$obj $expect" >&4
done 3>input 4>expect &&
GIT_ALTERNATE_OBJECT_DIRECTORIES=$alt \
git "$@" cat-file --batch-check='%(objectname) %(objecttype)' \
<input >actual &&
test_cmp expect actual
}
test_expect_success 'create alternate repositories' '
git init --bare one.git &&
one=$(echo one | git -C one.git hash-object -w --stdin) &&
git init --bare two.git &&
two=$(echo two | git -C two.git hash-object -w --stdin)
'
test_expect_success 'objects inaccessible without alternates' '
check_obj "" <<-EOF
$one missing
$two missing
EOF
'
test_expect_success 'access alternate via absolute path' '
check_obj "$PWD/one.git/objects" <<-EOF
alternates: re-allow relative paths from environment Commit 670c359da (link_alt_odb_entry: handle normalize_path errors, 2016-10-03) regressed the handling of relative paths in the GIT_ALTERNATE_OBJECT_DIRECTORIES variable. It's not entirely clear this was ever meant to work, but it _has_ worked for several years, so this commit restores the original behavior. When we get a path in GIT_ALTERNATE_OBJECT_DIRECTORIES, we add it the path to the list of alternate object directories as if it were found in objects/info/alternates, but with one difference: we do not provide the link_alt_odb_entry() function with a base for relative paths. That function doesn't turn it into an absolute path, and we end up feeding the relative path to the strbuf_normalize_path() function. Most relative paths break out of the top-level directory (e.g., "../foo.git/objects"), and thus normalizing fails. Prior to 670c359da, we simply ignored the error, and due to the way normalize_path_copy() was implemented it happened to return the original path in this case. We then accessed the alternate objects using this relative path. By storing the relative path in the alt_odb list, the path is relative to wherever we happen to be at the time we do an object lookup. That means we look from $GIT_DIR in a bare repository, and from the top of the worktree in a non-bare repository. If this were being designed from scratch, it would make sense to pick a stable location (probably $GIT_DIR, or even the object directory) and use that as the relative base, turning the result into an absolute path. However, given the history, at this point the minimal fix is to match the pre-670c359da behavior. We can do this simply by ignoring the error when we have no relative base and using the original value (which we now reliably have, thanks to strbuf_normalize_path()). That still leaves us with a relative path that foils our duplicate detection, and may act strangely if we ever chdir() later in the process. We could solve that by storing an absolute path based on getcwd(). That may be a good future direction; for now we'll do just the minimum to fix the regression. The new t5615 script demonstrates the fix in its final three tests. Since we didn't have any tests of the alternates environment variable at all, it also adds some tests of absolute paths. Reported-by: Bryan Turner <bturner@atlassian.com> Signed-off-by: Jeff King <peff@peff.net>
2016-11-08 05:50:17 +01:00
$one blob
$two missing
EOF
'
test_expect_success 'access multiple alternates' '
check_obj "$PWD/one.git/objects:$PWD/two.git/objects" <<-EOF
alternates: re-allow relative paths from environment Commit 670c359da (link_alt_odb_entry: handle normalize_path errors, 2016-10-03) regressed the handling of relative paths in the GIT_ALTERNATE_OBJECT_DIRECTORIES variable. It's not entirely clear this was ever meant to work, but it _has_ worked for several years, so this commit restores the original behavior. When we get a path in GIT_ALTERNATE_OBJECT_DIRECTORIES, we add it the path to the list of alternate object directories as if it were found in objects/info/alternates, but with one difference: we do not provide the link_alt_odb_entry() function with a base for relative paths. That function doesn't turn it into an absolute path, and we end up feeding the relative path to the strbuf_normalize_path() function. Most relative paths break out of the top-level directory (e.g., "../foo.git/objects"), and thus normalizing fails. Prior to 670c359da, we simply ignored the error, and due to the way normalize_path_copy() was implemented it happened to return the original path in this case. We then accessed the alternate objects using this relative path. By storing the relative path in the alt_odb list, the path is relative to wherever we happen to be at the time we do an object lookup. That means we look from $GIT_DIR in a bare repository, and from the top of the worktree in a non-bare repository. If this were being designed from scratch, it would make sense to pick a stable location (probably $GIT_DIR, or even the object directory) and use that as the relative base, turning the result into an absolute path. However, given the history, at this point the minimal fix is to match the pre-670c359da behavior. We can do this simply by ignoring the error when we have no relative base and using the original value (which we now reliably have, thanks to strbuf_normalize_path()). That still leaves us with a relative path that foils our duplicate detection, and may act strangely if we ever chdir() later in the process. We could solve that by storing an absolute path based on getcwd(). That may be a good future direction; for now we'll do just the minimum to fix the regression. The new t5615 script demonstrates the fix in its final three tests. Since we didn't have any tests of the alternates environment variable at all, it also adds some tests of absolute paths. Reported-by: Bryan Turner <bturner@atlassian.com> Signed-off-by: Jeff King <peff@peff.net>
2016-11-08 05:50:17 +01:00
$one blob
$two blob
EOF
'
# bare paths are relative from $GIT_DIR
test_expect_success 'access alternate via relative path (bare)' '
git init --bare bare.git &&
check_obj "../one.git/objects" -C bare.git <<-EOF
$one blob
EOF
'
# non-bare paths are relative to top of worktree
test_expect_success 'access alternate via relative path (worktree)' '
git init worktree &&
check_obj "../one.git/objects" -C worktree <<-EOF
$one blob
EOF
'
# path is computed after moving to top-level of worktree
test_expect_success 'access alternate via relative path (subdir)' '
mkdir subdir &&
check_obj "one.git/objects" -C subdir <<-EOF
$one blob
EOF
'
alternates: accept double-quoted paths We read lists of alternates from objects/info/alternates files (delimited by newline), as well as from the GIT_ALTERNATE_OBJECT_DIRECTORIES environment variable (delimited by colon or semi-colon, depending on the platform). There's no mechanism for quoting the delimiters, so it's impossible to specify an alternate path that contains a colon in the environment, or one that contains a newline in a file. We've lived with that restriction for ages because both alternates and filenames with colons are relatively rare, and it's only a problem when the two meet. But since 722ff7f87 (receive-pack: quarantine objects until pre-receive accepts, 2016-10-03), which builds on the alternates system, every push causes the receiver to set GIT_ALTERNATE_OBJECT_DIRECTORIES internally. It would be convenient to have some way to quote the delimiter so that we can represent arbitrary paths. The simplest thing would be an escape character before a quoted delimiter (e.g., "\:" as a literal colon). But that creates a backwards compatibility problem: any path which uses that escape character is now broken, and we've just shifted the problem. We could choose an unlikely escape character (e.g., something from the non-printable ASCII range), but that's awkward to use. Instead, let's treat names as unquoted unless they begin with a double-quote, in which case they are interpreted via our usual C-stylke quoting rules. This also breaks backwards-compatibility, but in a smaller way: it only matters if your file has a double-quote as the very _first_ character in the path (whereas an escape character is a problem anywhere in the path). It's also consistent with many other parts of git, which accept either a bare pathname or a double-quoted one, and the sender can choose to quote or not as required. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-12 20:52:22 +01:00
# set variables outside test to avoid quote insanity; the \057 is '/',
# which doesn't need quoting, but just confirms that de-quoting
# is working.
quoted='"one.git\057objects"'
unquoted='two.git/objects'
test_expect_success 'mix of quoted and unquoted alternates' '
check_obj "$quoted:$unquoted" <<-EOF
$one blob
$two blob
'
test_expect_success !MINGW 'broken quoting falls back to interpreting raw' '
alternates: accept double-quoted paths We read lists of alternates from objects/info/alternates files (delimited by newline), as well as from the GIT_ALTERNATE_OBJECT_DIRECTORIES environment variable (delimited by colon or semi-colon, depending on the platform). There's no mechanism for quoting the delimiters, so it's impossible to specify an alternate path that contains a colon in the environment, or one that contains a newline in a file. We've lived with that restriction for ages because both alternates and filenames with colons are relatively rare, and it's only a problem when the two meet. But since 722ff7f87 (receive-pack: quarantine objects until pre-receive accepts, 2016-10-03), which builds on the alternates system, every push causes the receiver to set GIT_ALTERNATE_OBJECT_DIRECTORIES internally. It would be convenient to have some way to quote the delimiter so that we can represent arbitrary paths. The simplest thing would be an escape character before a quoted delimiter (e.g., "\:" as a literal colon). But that creates a backwards compatibility problem: any path which uses that escape character is now broken, and we've just shifted the problem. We could choose an unlikely escape character (e.g., something from the non-printable ASCII range), but that's awkward to use. Instead, let's treat names as unquoted unless they begin with a double-quote, in which case they are interpreted via our usual C-stylke quoting rules. This also breaks backwards-compatibility, but in a smaller way: it only matters if your file has a double-quote as the very _first_ character in the path (whereas an escape character is a problem anywhere in the path). It's also consistent with many other parts of git, which accept either a bare pathname or a double-quoted one, and the sender can choose to quote or not as required. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-12 20:52:22 +01:00
mv one.git \"one.git &&
check_obj \"one.git/objects <<-EOF
$one blob
EOF
'
alternates: re-allow relative paths from environment Commit 670c359da (link_alt_odb_entry: handle normalize_path errors, 2016-10-03) regressed the handling of relative paths in the GIT_ALTERNATE_OBJECT_DIRECTORIES variable. It's not entirely clear this was ever meant to work, but it _has_ worked for several years, so this commit restores the original behavior. When we get a path in GIT_ALTERNATE_OBJECT_DIRECTORIES, we add it the path to the list of alternate object directories as if it were found in objects/info/alternates, but with one difference: we do not provide the link_alt_odb_entry() function with a base for relative paths. That function doesn't turn it into an absolute path, and we end up feeding the relative path to the strbuf_normalize_path() function. Most relative paths break out of the top-level directory (e.g., "../foo.git/objects"), and thus normalizing fails. Prior to 670c359da, we simply ignored the error, and due to the way normalize_path_copy() was implemented it happened to return the original path in this case. We then accessed the alternate objects using this relative path. By storing the relative path in the alt_odb list, the path is relative to wherever we happen to be at the time we do an object lookup. That means we look from $GIT_DIR in a bare repository, and from the top of the worktree in a non-bare repository. If this were being designed from scratch, it would make sense to pick a stable location (probably $GIT_DIR, or even the object directory) and use that as the relative base, turning the result into an absolute path. However, given the history, at this point the minimal fix is to match the pre-670c359da behavior. We can do this simply by ignoring the error when we have no relative base and using the original value (which we now reliably have, thanks to strbuf_normalize_path()). That still leaves us with a relative path that foils our duplicate detection, and may act strangely if we ever chdir() later in the process. We could solve that by storing an absolute path based on getcwd(). That may be a good future direction; for now we'll do just the minimum to fix the regression. The new t5615 script demonstrates the fix in its final three tests. Since we didn't have any tests of the alternates environment variable at all, it also adds some tests of absolute paths. Reported-by: Bryan Turner <bturner@atlassian.com> Signed-off-by: Jeff King <peff@peff.net>
2016-11-08 05:50:17 +01:00
test_done