git/notes.c, branch v2.15.2

Merge branch 'mh/notes-cleanup'

2017-09-19T01:47:52Z

Code clean-up. * mh/notes-cleanup: load_subtree(): check that `prefix_len` is in the expected range load_subtree(): declare some variables to be `size_t` hex_to_bytes(): simpler replacement for `get_oid_hex_segment()` get_oid_hex_segment(): don't pad the rest of `oid` load_subtree(): combine some common code get_oid_hex_segment(): return 0 on success load_subtree(): only consider blobs to be potential notes load_subtree(): check earlier whether an internal node is a tree entry load_subtree(): separate logic for internal vs. terminal entries load_subtree(): fix incorrect comment load_subtree(): reduce the scope of some local variables load_subtree(): remove unnecessary conditional notes: make GET_NIBBLE macro more robust

load_subtree(): check that `prefix_len` is in the expected range

2017-09-08T18:16:13Z

This value, which is stashed in the last byte of an object_id hash, gets handed around a lot. So add a sanity check before using it in `load_subtree()`. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_subtree(): declare some variables to be `size_t`

2017-08-26T16:21:01Z

* `prefix_len` * `path_len` * `i` It's good hygiene. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

hex_to_bytes(): simpler replacement for `get_oid_hex_segment()`

2017-08-26T16:21:01Z

Now that `get_oid_hex_segment()` does less, it makes sense to rename it and simplify its semantics: * Instead of a `hex_len` parameter, which was the number of hex characters (and had to be even), use a `len` parameter, which is the number of resulting bytes. This removes then need for the check that `hex_len` is even and to divide it by two to determine the number of bytes. For good hygiene, declare the `len` parameter to be `size_t` instead of `unsigned int`. * Change the order of the arguments to the more traditional (dst, src, len). * Rename the function to `hex_to_bytes()`. * Remove a loop variable: just count `len` down instead. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

get_oid_hex_segment(): don't pad the rest of `oid`

2017-08-26T16:21:01Z

Remove the feature of `get_oid_hex_segment()` that it pads the rest of the `oid` argument with zeros. Instead, do this at the caller who needs it. This makes the functionality of this function more coherent and removes the need for its `oid_len` argument. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_subtree(): combine some common code

2017-08-26T16:21:01Z

Write the length into `object_oid` (before copying) rather than `l->key_oid` (after copying). Then combine some code from the two `if` blocks. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

get_oid_hex_segment(): return 0 on success

2017-08-26T16:21:01Z

Nobody cares about the return value of get_oid_hex_segment() except to check whether it failed. So just return 0 on success. And while we're updating its docstring, update it for some argument renaming that happened a while ago. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_subtree(): only consider blobs to be potential notes

2017-08-26T16:21:01Z

The old code converted any entry whose path constituted a full SHA-1 as a leaf node, without regard for the type of the entry. But only blobs can be notes. So treat entries whose paths *look like* notes paths but that are not blobs as non-notes. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_subtree(): check earlier whether an internal node is a tree entry

2017-08-26T16:21:01Z

If an entry is not a tree entry, then it cannot possibly be an internal node. But the old code checked this condition only after allocating a leaf_node object and therefore leaked that memory. Instead, check before even entering this branch of the code. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

load_subtree(): separate logic for internal vs. terminal entries

2017-08-26T16:21:01Z

There are only two legitimate notes path components: * A hexadecimal string that fills the rest of the SHA-1 * A two-digit hexadecimal string that constitutes another internal node. So handle those two cases at the top level, and reject others as non-notes without trying to parse them. The logic separation also simplifies upcoming changes. This prevents us from leaking memory for a leaf_node in the case of wrong-sized paths. There are still memory leaks in this code; they will be fixed in upcoming commits. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano