git-svn: search --authors-prog in PATH too

In 36db1eddf9 ("git-svn: add --authors-prog option", 2009-05-14) the path
to authors-prog was made absolute because git-svn changes the current
directory in some situations. This makes sense if the program is part of
the repository but prevents searching via $PATH.

The old behaviour is still retained, but if the file does not exists, then
authors-prog is searched for in $PATH as any other command.

Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Eric Wong <e@80x24.org>

Documentation/git-svn.txt

@@ -657,6 +657,11 @@ config key: svn.authorsfile
 	expected to return a single line of the form "Name <email>",
 	which will be treated as if included in the authors file.
 +
+Due to historical reasons a relative 'filename' is first searched
+relative to the current directory for 'init' and 'clone' and relative
+to the root of the working tree for 'fetch'. If 'filename' is
+not found, it is searched like any other command in '$PATH'.
++
 [verse]
 config key: svn.authorsProg
 

git-svn.perl

@@ -374,7 +374,8 @@ version() if $_version;
 usage(1) unless defined $cmd;
 load_authors() if $_authors;
 if (defined $_authors_prog) {
-	$_authors_prog = "'" . File::Spec->rel2abs($_authors_prog) . "'";
+	my $abs_file = File::Spec->rel2abs($_authors_prog);
+	$_authors_prog = "'" . $abs_file . "'" if -x $abs_file;
 }
 
 unless ($cmd =~ /^(?:clone|init|multi-init|commit-diff)$/) {