Re: assert failed in submodule edge case

2015-04-16 Thread Jens Lehmann

Am 13.04.2015 um 18:55 schrieb Dennis Kaarsemaker:

Reported by djanos_ in #git: git add segfaults when you manage to
confuse it with a submodule in the index that is no longer a submodule.

Here's his script to reproduce the segfault:

mkdir segfault
cd segfault

mkdir subrepo
cd subrepo

git init .
echo a > a
git add a
git commit -m "a"

cd ..

git init .
git add .


If you add a "git rm -f --cached subrepo" here the problem goes away.


cd subrepo
rm -rf .git
git add .

This last git add will now barf:
git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= item->len && 
item->prefix <= item->len' failed.

These all work as I think they are intended to:
$ git -C segfault add subrepo/a
fatal: Pathspec 'subrepo/a' is in submodule 'subrepo'
$ git -C segfault/subrepo add a
fatal: Pathspec 'a' is in submodule 'subrepo'

And this does nothing, it also doesn't crash:

$ git -C segfault add subrepo

GDB backtrace below, this is with next as of e6f3401.

Starting program: /home/dennis/code/git/git -C segfault/subrepo add .
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= item->len && 
item->prefix <= item->len' failed.

Program received signal SIGABRT, Aborted.
0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:56
56  ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x7702c528 in __GI_abort () at abort.c:89
#2  0x77023ce6 in __assert_fail_base (fmt=0x77173c08 "%s%s%s:%u: 
%s%sAssertion `%s' failed.\n%n",
 assertion=assertion@entry=0x560660 "item->nowildcard_len <= item->len && item->prefix <= 
item->len", file=file@entry=0x560826 "pathspec.c", line=line@entry=317,
 function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> 
"prefix_pathspec") at assert.c:92
#3  0x77023d92 in __GI___assert_fail (assertion=assertion@entry=0x560660 "item->nowildcard_len 
<= item->len && item->prefix <= item->len",
 file=file@entry=0x560826 "pathspec.c", line=line@entry=317, 
function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> "prefix_pathspec") at 
assert.c:101
#4  0x004d6a37 in prefix_pathspec (elt=0x7fffdaf1 ".", prefixlen=8, 
prefix=0x7dd09f "subrepo/", flags=50, raw=0x7fffd648,
 p_short_magic=, item=) at pathspec.c:316
#5  parse_pathspec (pathspec=pathspec@entry=0x7fffd240, 
magic_mask=magic_mask@entry=0, flags=flags@entry=50, prefix=prefix@entry=0x7dd09f 
"subrepo/",
 argv=argv@entry=0x7fffd648) at pathspec.c:417
#6  0x0040698c in cmd_add (argc=, argv=0x7fffd648, 
prefix=0x7dd09f "subrepo/") at builtin/add.c:370
#7  0x00406001 in run_builtin (argv=0x7fffd640, argc=2, p=0x79d740 
) at git.c:350
#8  handle_builtin (argc=2, argv=0x7fffd640) at git.c:532
#9  0x00405151 in run_argv (argv=0x7fffd458, argcp=0x7fffd43c) 
at git.c:578
#10 main (argc=2, av=) at git.c:686

I dig a bit into pathspec.c and it looks like the
PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE code in prefix_pathspec is only
stripping out paths inside the submodule, not the submodule itself.

I also guess that it shouldn't as otherwise you can't ever 'git add' a
submodule. So I have no idea how to proceed, or even what the correct
behaviour of 'git add' should be in this case. I do think that failing
an assert() to tell a user he's doing something unexpected/silly/wrong
isn't the right thing to do though :)


The problem seems to be that "subrepo" is still registered as a
submodule in the index. But we should see a proper error message
instead of an assert in that case ... CCed Duy who knows much
more about pathspec.c than me.
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Re: assert failed in submodule edge case

2015-04-13 Thread Dennis Kaarsemaker
Err, ignore the 'segfault' bits. It's an assert() failure. He called it
a segfault at first and that got stuck in my head.

On ma, 2015-04-13 at 18:55 +0200, Dennis Kaarsemaker wrote:
> Reported by djanos_ in #git: git add segfaults when you manage to
> confuse it with a submodule in the index that is no longer a submodule.
> 
> Here's his script to reproduce the segfault:
> 
> mkdir segfault
> cd segfault
> 
> mkdir subrepo
> cd subrepo
> 
> git init .
> echo a > a
> git add a
> git commit -m "a"
> 
> cd ..
> 
> git init .
> git add .
> 
> cd subrepo
> rm -rf .git
> git add .
> 
> This last git add will now barf:
> git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= 
> item->len && item->prefix <= item->len' failed.
> 
> These all work as I think they are intended to:
> $ git -C segfault add subrepo/a
> fatal: Pathspec 'subrepo/a' is in submodule 'subrepo'
> $ git -C segfault/subrepo add a
> fatal: Pathspec 'a' is in submodule 'subrepo'
> 
> And this does nothing, it also doesn't crash:
> 
> $ git -C segfault add subrepo
> 
> GDB backtrace below, this is with next as of e6f3401.
> 
> Starting program: /home/dennis/code/git/git -C segfault/subrepo add .
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= 
> item->len && item->prefix <= item->len' failed.
> 
> Program received signal SIGABRT, Aborted.
> 0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
> 56../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
> (gdb) bt
> #0  0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
> ../nptl/sysdeps/unix/sysv/linux/raise.c:56
> #1  0x7702c528 in __GI_abort () at abort.c:89
> #2  0x77023ce6 in __assert_fail_base (fmt=0x77173c08 "%s%s%s:%u: 
> %s%sAssertion `%s' failed.\n%n", 
> assertion=assertion@entry=0x560660 "item->nowildcard_len <= item->len && 
> item->prefix <= item->len", file=file@entry=0x560826 "pathspec.c", 
> line=line@entry=317, 
> function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> 
> "prefix_pathspec") at assert.c:92
> #3  0x77023d92 in __GI___assert_fail 
> (assertion=assertion@entry=0x560660 "item->nowildcard_len <= item->len && 
> item->prefix <= item->len", 
> file=file@entry=0x560826 "pathspec.c", line=line@entry=317, 
> function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> 
> "prefix_pathspec") at assert.c:101
> #4  0x004d6a37 in prefix_pathspec (elt=0x7fffdaf1 ".", 
> prefixlen=8, prefix=0x7dd09f "subrepo/", flags=50, raw=0x7fffd648, 
> p_short_magic=, item=) at pathspec.c:316
> #5  parse_pathspec (pathspec=pathspec@entry=0x7fffd240, 
> magic_mask=magic_mask@entry=0, flags=flags@entry=50, 
> prefix=prefix@entry=0x7dd09f "subrepo/", 
> argv=argv@entry=0x7fffd648) at pathspec.c:417
> #6  0x0040698c in cmd_add (argc=, argv=0x7fffd648, 
> prefix=0x7dd09f "subrepo/") at builtin/add.c:370
> #7  0x00406001 in run_builtin (argv=0x7fffd640, argc=2, 
> p=0x79d740 ) at git.c:350
> #8  handle_builtin (argc=2, argv=0x7fffd640) at git.c:532
> #9  0x00405151 in run_argv (argv=0x7fffd458, 
> argcp=0x7fffd43c) at git.c:578
> #10 main (argc=2, av=) at git.c:686
> 
> I dig a bit into pathspec.c and it looks like the
> PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE code in prefix_pathspec is only
> stripping out paths inside the submodule, not the submodule itself.
> 
> I also guess that it shouldn't as otherwise you can't ever 'git add' a
> submodule. So I have no idea how to proceed, or even what the correct
> behaviour of 'git add' should be in this case. I do think that failing
> an assert() to tell a user he's doing something unexpected/silly/wrong
> isn't the right thing to do though :)
> 




-- 
Dennis Kaarsemaker
www.kaarsemaker.net

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assert failed in submodule edge case

2015-04-13 Thread Dennis Kaarsemaker
Reported by djanos_ in #git: git add segfaults when you manage to
confuse it with a submodule in the index that is no longer a submodule.

Here's his script to reproduce the segfault:

mkdir segfault
cd segfault

mkdir subrepo
cd subrepo

git init .
echo a > a
git add a
git commit -m "a"

cd ..

git init .
git add .

cd subrepo
rm -rf .git
git add .

This last git add will now barf:
git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= 
item->len && item->prefix <= item->len' failed.

These all work as I think they are intended to:
$ git -C segfault add subrepo/a
fatal: Pathspec 'subrepo/a' is in submodule 'subrepo'
$ git -C segfault/subrepo add a
fatal: Pathspec 'a' is in submodule 'subrepo'

And this does nothing, it also doesn't crash:

$ git -C segfault add subrepo

GDB backtrace below, this is with next as of e6f3401.

Starting program: /home/dennis/code/git/git -C segfault/subrepo add .
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
git: pathspec.c:317: prefix_pathspec: Assertion `item->nowildcard_len <= 
item->len && item->prefix <= item->len' failed.

Program received signal SIGABRT, Aborted.
0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:56
56  ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x7702ae37 in __GI_raise (sig=sig@entry=6) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x7702c528 in __GI_abort () at abort.c:89
#2  0x77023ce6 in __assert_fail_base (fmt=0x77173c08 "%s%s%s:%u: 
%s%sAssertion `%s' failed.\n%n", 
assertion=assertion@entry=0x560660 "item->nowildcard_len <= item->len && 
item->prefix <= item->len", file=file@entry=0x560826 "pathspec.c", 
line=line@entry=317, 
function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> 
"prefix_pathspec") at assert.c:92
#3  0x77023d92 in __GI___assert_fail 
(assertion=assertion@entry=0x560660 "item->nowildcard_len <= item->len && 
item->prefix <= item->len", 
file=file@entry=0x560826 "pathspec.c", line=line@entry=317, 
function=function@entry=0x560850 <__PRETTY_FUNCTION__.22237> "prefix_pathspec") 
at assert.c:101
#4  0x004d6a37 in prefix_pathspec (elt=0x7fffdaf1 ".", prefixlen=8, 
prefix=0x7dd09f "subrepo/", flags=50, raw=0x7fffd648, 
p_short_magic=, item=) at pathspec.c:316
#5  parse_pathspec (pathspec=pathspec@entry=0x7fffd240, 
magic_mask=magic_mask@entry=0, flags=flags@entry=50, 
prefix=prefix@entry=0x7dd09f "subrepo/", 
argv=argv@entry=0x7fffd648) at pathspec.c:417
#6  0x0040698c in cmd_add (argc=, argv=0x7fffd648, 
prefix=0x7dd09f "subrepo/") at builtin/add.c:370
#7  0x00406001 in run_builtin (argv=0x7fffd640, argc=2, p=0x79d740 
) at git.c:350
#8  handle_builtin (argc=2, argv=0x7fffd640) at git.c:532
#9  0x00405151 in run_argv (argv=0x7fffd458, argcp=0x7fffd43c) 
at git.c:578
#10 main (argc=2, av=) at git.c:686

I dig a bit into pathspec.c and it looks like the
PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE code in prefix_pathspec is only
stripping out paths inside the submodule, not the submodule itself.

I also guess that it shouldn't as otherwise you can't ever 'git add' a
submodule. So I have no idea how to proceed, or even what the correct
behaviour of 'git add' should be in this case. I do think that failing
an assert() to tell a user he's doing something unexpected/silly/wrong
isn't the right thing to do though :)

-- 
Dennis Kaarsemaker
www.kaarsemaker.net

--
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