Re: newbie question - git-pull and local branch merge
"Pelle Svensson" <pelle2004@gmail.com> writes:
> Problem is that git-pull failed to merge closed to what you describe in case 2
> and I really like to know hat has been done between the 2 last versions
> on the Linus side.
Let me have a set of illustrations (I cannot think without one X-<). You forked off of Linus's tip some time ago (time flows from left to right):
x---x---x---x Pelle
/
---o Linusin the meantime Linus's tip progressed:
x---x---x---x Pelle
/
---o---*---*---*---* Linusand you are trying to create a merge 'M' by pulling from him:
x---x---x---x...M Pelle
/ /
---o---*---*---*---* LinusThe 'pull' conflicted so you do not have 'M' commit yet.
In such a situation, a command that helps to view what happened to the files that got conflicted is:
$ git log -p --merge
By default it uses the "unmreged" files (in your case, arch/arm/mach-ep93xx/core.c and include/asm-arm/system.h). You can limit the output by giving specific paths:
$ git log -p --merge include/asm-arm/system.h
This would show changes from both sides (i.e. commits marked with 'x' and '*').
Show 7 quoted lines
> The problematic file is include/asm-arm/system.h
>
> I attached some output below. Last (D) is a file diff between the time when
> I first pulled the Linus tree and a copy of that which I'm now working in.
> I think the resolve/edit part is easy because Linus tree seem to added
> an extern declaration of 'adjust_cr' closed to line 152 and the other
> conflict code (++<<<...) should be removed.
> But is it not possible to show changes/diff version by version of
> what has been done in the Linus tree?
I think "log --merge" is what you want, but if you do not want to see your own changes, you can:
$ git log -p ..MERGE_HEAD -- include/asm-arm/system.h
The notation "..MERGE_HEAD" in the above is a short-hand for "HEAD..MERGE_HEAD", and "A..B" means "show commits reachable from B but I am not interested in the ones reachable from A", so it shows what are in MERGE_HEAD but not in your HEAD, which I think is exactly what you want. And paths on the command line limits the commits considered by the command to only those that touch the specified paths.
Show 16 quoted lines
> A. git-status output
> B. git-diff output
> C. And if I do git-pull again
> D. diff output between file stamp 12-dec and 21-dec
>
> A. git-status output
> ============
>
> # On branch refs/heads/ep93xx-pmp
> #
> # Updated but not checked in:
> # (will commit)
> #
> # modified: Documentation/block/biodoc.txt
> # ...
> # modified: sound/usb/usbaudio.c
These are list of paths that got changed on Linus's side and either you did not change at all, or had changes that were cleanly merged.
Show 11 quoted lines
> #
> #
> # Changed but not updated:
> # (use git-update-index to mark for commit)
> #
> # unmerged: arch/arm/mach-ep93xx/core.c
> # modified: arch/arm/mach-ep93xx/ep93xx_devices.c
> # modified: drivers/net/arm/ep93xx_eth.c
> # modified: drivers/video/ep93xxfb.c
> # unmerged: include/asm-arm/system.h
> # modified: include/asm-arm/system.h
I thought you had local modification to two paths, but this shows four 'modified:' files. Please make sure these four 'modified' files were not modified on the Linus's side (e.g. "git log -p ..MERGE_HEAD -- drivers/video/ep93xxfb.c" as shown above), and only contains your own changes.
Two 'unmerged' paths are what you changed and committed in some of the 'x' commits in the above picture and also had modifications on Linus's side.
Show 15 quoted lines
> B. git-diff output
> ==========
>
> diff --cc include/asm-arm/system.h
> index 04d6d2c,aa223fc..0000000
> --- a/include/asm-arm/system.h
> +++ b/include/asm-arm/system.h
> @@@ -170,31 -178,6 +178,34 @@@
> : : "r" (val) : "cc");
> }
>
> ++<<<<<<< HEAD/include/asm-arm/system.h
> +extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
> +extern unsigned long cr_alignment; /* defined in entry-armv.S */
> ...
You added this section and Linus's side did not have it.
Show 10 quoted lines
> ...
> + raw_local_irq_restore(flags);
> +}
> +#endif
> +
> ++=======
> ++>>>>>>> 9bfb18392ef586467277fa25d8f3a7a93611f6df/include/asm-arm/system.h
> #define UDBG_UNDEFINED (1 << 0)
> #define UDBG_SYSCALL (1 << 1)
> #define UDBG_BADABORT (1 << 2)
So as you said, it seems appropriate to just keep your changes. by removing the conflict markers.
Show 18 quoted lines
> C. And if I do git-pull again
> =================
>
> Trying really trivial in-index merge...
> arch/arm/mach-ep93xx/core.c: needs merge
> arch/arm/mach-ep93xx/ep93xx_devices.c: needs update
> drivers/net/arm/ep93xx_eth.c: needs update
> drivers/video/ep93xxfb.c: needs update
> include/asm-arm/system.h: needs merge
> Nope.
> Merging HEAD with 3e67c0987d7567ad666641164a153dca9a43b11d
> Merging:
> 87d627b097b52c47610037bfb890940752fbf4c8 added .orig to gitignore
> 3e67c0987d7567ad666641164a153dca9a43b11d [PATCH] truncate: clear page
> dirtiness before running try_to_free_buffers()
> found 1 common ancestor(s):
> f238085415c56618e042252894f2fcc971add645 Merge branch 'for-linus' of
> git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Was this the end of the output? I hope you hit this message:
die("Entry '%s' not uptodate. Cannot merge.", ce->name);and the second pull did not make any change. At least that is how it ought to work. You might have spotted a bug that was uncovered only because no git old timers would even imagine running 'pull' again after getting conflicts from the first attempt, but I suspect that the above quoted output is not showing the end of the output.
