git/git.c, branch v2.12.3

Merge branch 'sb/unpack-trees-super-prefix'

2017-02-03T19:25:18Z

"git read-tree" and its underlying unpack_trees() machinery learned to report problematic paths prefixed with the --super-prefix option. * sb/unpack-trees-super-prefix: unpack-trees: support super-prefix option t1001: modernize style t1000: modernize style read-tree: use OPT_BOOL instead of OPT_SET_INT

Merge branch 'js/difftool-builtin'

2017-01-31T21:15:00Z

Rewrite a scripted porcelain "git difftool" in C. * js/difftool-builtin: difftool: hack around -Wzero-length-format warning difftool: retire the scripted version difftool: implement the functionality in the builtin difftool: add a skeleton for the upcoming builtin

unpack-trees: support super-prefix option

2017-01-25T20:33:33Z

In the future we want to support working tree operations within submodules, e.g. "git checkout --recurse-submodules", which will update the submodule to the commit as recorded in its superproject. In the submodule the unpack-tree operation is carried out as usual, but the reporting to the user needs to prefix any path with the superproject. The mechanism for this is the super-prefix. (see 74866d757, git: make super-prefix option) Add support for the super-prefix option for commands that unpack trees by wrapping any path output in unpacking trees in the newly introduced super_prefixed function. This new function prefixes any path with the super-prefix if there is one. Assuming the submodule case doesn't happen in the majority of the cases, we'd want to have a fast behavior for no super prefix, i.e. no reallocation/copying, but just returning path. Another aspect of introducing the `super_prefixed` function is to consider who owns the memory and if this is the right place where the path gets modified. As the super prefix ought to change the output behavior only and not the actual unpack tree part, it is fine to be that late in the line. As we get passed in 'const char *path', we cannot change the path itself, which means in case of a super prefix we have to copy over the path. We need two static buffers in that function as the error messages contain at most two paths. For testing purposes enable it in read-tree, which has no output of paths other than an unpack-trees.c. These are all converted in this patch. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano

difftool: retire the scripted version

2017-01-19T21:23:43Z

It served its purpose, but now we have a builtin difftool. Time for the Perl script to enjoy Florida. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'jk/execv-dashed-external'

2017-01-18T23:12:16Z

Typing ^C to pager, which usually does not kill it, killed Git and took the pager down as a collateral damage in certain process-tree structure. This has been fixed. * jk/execv-dashed-external: execv_dashed_external: wait for child on signal death execv_dashed_external: stop exiting with negative code execv_dashed_external: use child_process struct

Merge branch 'bw/grep-recurse-submodules'

2017-01-18T23:12:11Z

"git grep" has been taught to optionally recurse into submodules. * bw/grep-recurse-submodules: grep: search history of moved submodules grep: enable recurse-submodules to work on objects grep: optionally recurse into submodules grep: add submodules as a grep source type submodules: load gitmodules file from commit sha1 submodules: add helper to determine if a submodule is initialized submodules: add helper to determine if a submodule is populated real_path: canonicalize directory separators in root parts real_path: have callers use real_pathdup and strbuf_realpath real_path: create real_pathdup real_path: convert real_path_internal to strbuf_realpath real_path: resolve symlinks by hand

difftool: add a skeleton for the upcoming builtin

2017-01-17T21:32:47Z

This adds a builtin difftool that still falls back to the legacy Perl version, which has been renamed to `legacy-difftool`. The idea is that the new, experimental, builtin difftool immediately hands off to the legacy difftool for now, unless the config variable difftool.useBuiltin is set to true. This feature flag will be used in the upcoming Git for Windows v2.11.0 release, to allow early testers to opt-in to use the builtin difftool and flesh out any bugs. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

Merge branch 'sb/submodule-embed-gitdir'

2017-01-10T23:24:28Z

A new submodule helper "git submodule embedgitdirs" to make it easier to move embedded .git/ directory for submodules in a superproject to .git/modules/ (and point the latter with the former that is turned into a "gitdir:" file) has been added. * sb/submodule-embed-gitdir: worktree: initialize return value for submodule_uses_worktrees submodule: add absorb-git-dir function move connect_work_tree_and_git_dir to dir.h worktree: check if a submodule uses worktrees test-lib-functions.sh: teach test_commit -C submodule helper: support super prefix submodule: use absolute path for computing relative path connecting

execv_dashed_external: wait for child on signal death

2017-01-09T21:41:40Z

When you hit ^C to interrupt a git command going to a pager, this usually leaves the pager running. But when a dashed external is in use, the pager ends up in a funny state and quits (but only after eating one more character from the terminal!). This fixes it. Explaining the reason will require a little background. When git runs a pager, it's important for the git process to hang around and wait for the pager to finish, even though it has no more data to feed it. This is because git spawns the pager as a child, and thus the git process is the session leader on the terminal. After it dies, the pager will finish its current read from the terminal (eating the one character), and then get EIO trying to read again. When you hit ^C, that sends SIGINT to git and to the pager, and it's a similar situation. The pager ignores it, but the git process needs to hang around until the pager is done. We addressed that long ago in a3da882120 (pager: do wait_for_pager on signal death, 2009-01-22). But when you have a dashed external (or an alias pointing to a builtin, which will re-exec git for the builtin), there's an extra process in the mix. For instance, running: $ git -c alias.l=log l will end up with a process tree like: git (parent) \ git-log (child) \ less (pager) If you hit ^C, SIGINT goes to all of them. The pager ignores it, and the child git process will end up in wait_for_pager(). But the parent git process will die, and the usual EIO trouble happens. So we really want the parent git process to wait_for_pager(), but of course it doesn't know anything about the pager at all, since it was started by the child. However, we can have it wait on the git-log child, which in turn is waiting on the pager. And that's what this patch does. There are a few design decisions here worth explaining: 1. The new feature is attached to run-command's clean_on_exit feature. Partly this is convenience, since that feature already has a signal handler that deals with child cleanup. But it's also a meaningful connection. The main reason that dashed externals use clean_on_exit is to bind the two processes together. If somebody kills the parent with a signal, we propagate that to the child (in this instance with SIGINT, we do propagate but it doesn't matter because the original signal went to the whole process group). Likewise, we do not want the parent to go away until the child has done so. In a traditional Unix world, we'd probably accomplish this binding by just having the parent execve() the child directly. But since that doesn't work on Windows, everything goes through run_command's more spawn-like interface. 2. We do _not_ automatically waitpid() on any clean_on_exit children. For dashed externals this makes sense; we know that the parent is doing nothing but waiting for the child to exit anyway. But with other children, it's possible that the child, after getting the signal, could be waiting on the parent to do something (like closing a descriptor). If we were to wait on such a child, we'd end up in a deadlock. So this errs on the side of caution, and lets callers enable the feature explicitly. 3. When we send children the cleanup signal, we send all the signals first, before waiting on any children. This is to avoid the case where one child might be waiting on another one to exit, causing a deadlock. We inform all of them that it's time to die before reaping any. In practice, there is only ever one dashed external run from a given process, so this doesn't matter much now. But it future-proofs us if other callers start using the wait_after_clean mechanism. There's no automated test here, because it would end up racy and unportable. But it's easy to reproduce the situation by running the log command given above and hitting ^C. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

execv_dashed_external: stop exiting with negative code

2017-01-09T21:41:35Z

When we try to exec a git sub-command, we pass along the status code from run_command(). But that may return -1 if we ran into an error with pipe() or execve(). This tends to work (and end up as 255 due to twos-complement wraparound and truncation), but in general it's probably a good idea to avoid negative exit codes for portability. We can easily translate to the normal generic "128" code we get when syscalls cause us to die. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano