Mercurial > hg
view tests/test-convert-svn-branches.t @ 42562:97ada9b8d51b stable 5.0.2
posix: always seek to EOF when opening a file in append mode
Python 3 already does this, so skip it there.
Consider the program:
#include <stdio.h>
int main() {
FILE *f = fopen("narf", "w");
fprintf(f, "narf\n");
fclose(f);
f = fopen("narf", "a");
printf("%ld\n", ftell(f));
fprintf(f, "troz\n");
printf("%ld\n", ftell(f));
return 0;
}
on macOS, FreeBSD, and Linux with glibc, this program prints
5
10
but on musl libc (Alpine Linux and probably others) this prints
0
10
By my reading of
https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html
this is technically correct, specifically:
> Opening a file with append mode (a as the first character in the
> mode argument) shall cause all subsequent writes to the file to be
> forced to the then current end-of-file, regardless of intervening
> calls to fseek().
in other words, the file position doesn't really matter in append-mode
files, and we can't depend on it being at all meaningful unless we
perform a seek() before tell() after open(..., 'a'). Experimentally
after a .write() we can do a .tell() and it'll always be reasonable,
but I'm unclear from reading the specification if that's a smart thing
to rely on. This matches what we do on Windows and what Python 3 does
for free, so let's just be consistent. Thanks to Yuya for the idea.
author | Augie Fackler <augie@google.com> |
---|---|
date | Mon, 08 Jul 2019 13:12:20 -0400 |
parents | 46da52f4b820 |
children |
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#require svn svn-bindings $ cat >> $HGRCPATH <<EOF > [extensions] > convert = > EOF $ svnadmin create svn-repo $ svnadmin load -q svn-repo < "$TESTDIR/svn/branches.svndump" Convert trunk and branches $ cat > branchmap <<EOF > old3 newbranch > > > EOF $ hg convert --branchmap=branchmap --datesort -r 10 svn-repo A-hg initializing destination A-hg repository scanning source... sorting... converting... 10 init projA 9 hello 8 branch trunk, remove c and dir 7 change a 6 change b 5 move and update c 4 move and update c 3 change b again 2 move to old2 1 move back to old 0 last change to a Test template keywords $ hg -R A-hg log --template '{rev} {svnuuid}{svnpath}@{svnrev}\n' 10 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@10 9 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@9 8 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old2@8 7 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@7 6 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@6 5 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@6 4 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@5 3 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@4 2 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@3 1 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@2 0 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@1 Convert again $ hg convert --branchmap=branchmap --datesort svn-repo A-hg scanning source... sorting... converting... 0 branch trunk@1 into old3 $ cd A-hg $ hg log -G --template 'branch={branches} {rev} {desc|firstline} files: {files}\n' o branch=newbranch 11 branch trunk@1 into old3 files: | | o branch= 10 last change to a files: a | | | | o branch=old 9 move back to old files: | | | | | o branch=old2 8 move to old2 files: | | | | | o branch=old 7 change b again files: b | | | | o | branch= 6 move and update c files: b | | | | | o branch=old 5 move and update c files: c | | | | | o branch=old 4 change b files: b | | | | o | branch= 3 change a files: a | | | | | o branch=old 2 branch trunk, remove c and dir files: c | |/ | o branch= 1 hello files: a b c dir/e |/ o branch= 0 init projA files: $ hg branches newbranch 11:a6d7cc050ad1 default 10:6e2b33404495 old 9:1b494af68c0b old2 8:5be40b8dcbf6 (inactive) $ hg tags -q tip $ cd .. Test hg failing to call itself $ HG=foobar hg convert svn-repo B-hg 2>&1 | grep abort abort: Mercurial failed to run itself, check hg executable is in PATH Convert 'trunk' to branch other than 'default' $ cat > branchmap <<EOF > default hgtrunk > > > EOF $ hg convert --branchmap=branchmap --datesort -r 10 svn-repo C-hg initializing destination C-hg repository scanning source... sorting... converting... 10 init projA 9 hello 8 branch trunk, remove c and dir 7 change a 6 change b 5 move and update c 4 move and update c 3 change b again 2 move to old2 1 move back to old 0 last change to a $ cd C-hg $ hg branches --template '{branch}\n' hgtrunk old old2 $ cd ..