tests/svn/svndump-move.sh

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.

#!/bin/sh
#
# Use this script to generate move.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
echo a > trunk/a
mkdir trunk/d1
mkdir trunk/d2
echo b > trunk/d1/b
echo c > trunk/d1/c
echo d > trunk/d2/d
cd ..

svnadmin create svn-repo
svnurl=file://`pwd`/svn-repo
svn import project-orig $svnurl -m "init projA"

svn co $svnurl project
cd project
# Build a module renaming chain which used to confuse the converter.
# Update svn repository
echo a >> trunk/a
echo c >> trunk/d1/c
svn ci -m commitbeforemove
svn mv $svnurl/trunk $svnurl/subproject -m movedtrunk
svn up
mkdir subproject/trunk
svn add subproject/trunk
svn ci -m createtrunk
mkdir subproject/branches
svn add subproject/branches
svn ci -m createbranches
svn mv $svnurl/subproject/d1 $svnurl/subproject/trunk/d1 -m moved1
svn mv $svnurl/subproject/d2 $svnurl/subproject/trunk/d2 -m moved2
svn up
echo b >> subproject/trunk/d1/b

svn rm subproject/trunk/d2
svn ci -m "changeb and rm d2"
svn mv $svnurl/subproject/trunk/d1 $svnurl/subproject/branches/d1 -m moved1again

if svn help copy | grep 'SRC\[@REV\]' > /dev/null 2>&1; then
    # SVN >= 1.5 replaced the -r REV syntax with @REV
    # Copy a file from a past revision
    svn copy $svnurl/subproject/trunk/d2/d@7 $svnurl/subproject/trunk -m copyfilefrompast
    # Copy a directory from a past revision
    svn copy $svnurl/subproject/trunk/d2@7 $svnurl/subproject/trunk -m copydirfrompast
else
    # Copy a file from a past revision
    svn copy -r 7 $svnurl/subproject/trunk/d2/d $svnurl/subproject/trunk -m copyfilefrompast
    # Copy a directory from a past revision
    svn copy -r 7 $svnurl/subproject/trunk/d2 $svnurl/subproject/trunk -m copydirfrompast
fi

# Copy a directory while removing a subdirectory
svn up
mkdir -p subproject/trunk/d3/d31
echo e > subproject/trunk/d3/d31/e
echo f > subproject/trunk/d3/f
svn add subproject/trunk/d3
svn ci -m "add d3"
svn copy subproject/trunk/d3 subproject/trunk/d4
svn rm subproject/trunk/d3/d31
svn ci -m "copy dir and remove subdir"

# Test directory moves
svn up
mkdir -p subproject/trunk/d4old
echo g > subproject/trunk/d4old/g
svn add subproject/trunk/d4old
svn ci -m "add d4old"
svn mv subproject/trunk/d4old subproject/trunk/d4new
svn ci -m "rename d4old into d4new"

cd ..

svnadmin dump svn-repo > ../move.svndump