[PATCH] git-remote-mediawiki: Fix a bug in a regexp
In Perl, '\n' is not a newline, but instead a literal backslash followed by an
n. As the output of rev-list --first-parent is line-oriented, what we want
here is a newline.
Signed-off-by: Célestin Matte celestin.ma...@ensimag.fr
Signed-off-by: Matthieu Moy matthieu@grenoble-inp.fr
---
contrib/mw-to-git/git-remote-mediawiki.perl |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/contrib/mw-to-git/git-remote-mediawiki.perl
b/contrib/mw-to-git/git-remote-mediawiki.perl
index 7af202f..a06bc31 100755
--- a/contrib/mw-to-git/git-remote-mediawiki.perl
+++ b/contrib/mw-to-git/git-remote-mediawiki.perl
@@ -1190,7 +1190,7 @@ sub mw_push_revision {
# history (linearized with --first-parent)
print STDERR Warning: no common ancestor, pushing complete
history\n;
my $history = run_git(rev-list --first-parent --children
$local);
- my @history = split('\n', $history);
+ my @history = split(/\n/, $history);
@history = @history[1..$#history];
foreach my $line (reverse @history) {
my @commit_info_split = split(/ |\n/, $line);
--
1.7.9.5
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Re: [PATCH] git-remote-mediawiki: Fix a bug in a regexp
Célestin Matte celestin.ma...@ensimag.fr writes: In Perl, '\n' is not a newline, but instead a literal backslash followed by an n. As the output of rev-list --first-parent is line-oriented, what we want here is a newline. This is right, but the code actually worked the way it was. I'm not sure, but my understanding is that '\n' is the string backslash followed by n, but interpreted as a regexp, it is a newline. The new code looks better than the old one, but the log message may be improved. In any case, Acked-by: Matthieu Moy matthieu@grenoble-inp.fr -- Matthieu Moy http://www-verimag.imag.fr/~moy/ -- To unsubscribe from this list: send the line unsubscribe git in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-remote-mediawiki: Fix a bug in a regexp
Le 08/06/2013 20:38, Matthieu Moy a écrit : This is right, but the code actually worked the way it was. I'm not sure, but my understanding is that '\n' is the string backslash followed by n, but interpreted as a regexp, it is a newline. The new code looks better than the old one, but the log message may be improved. Is this better? In Perl, '\n' is not a newline, but instead the string composed of a backslash followed by an n. To match newlines, one has to use the /\n/ regexp. As the output of rev-list --first-parent is line-oriented, what we want here is to match newlines, and not the \n string. -- Célestin Matte -- To unsubscribe from this list: send the line unsubscribe git in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-remote-mediawiki: Fix a bug in a regexp
On Sat, Jun 08, 2013 at 08:38:56PM +0200, Matthieu Moy wrote: Célestin Matte celestin.ma...@ensimag.fr writes: In Perl, '\n' is not a newline, but instead a literal backslash followed by an n. As the output of rev-list --first-parent is line-oriented, what we want here is a newline. This is right, but the code actually worked the way it was. I'm not sure, but my understanding is that '\n' is the string backslash followed by n, but interpreted as a regexp, it is a newline. Yes, the relevant doc (from perldoc -f split) is: The pattern /PATTERN/ may be replaced with an expression to specify patterns that vary at runtime. (To do runtime compilation only once, use /$variable/o.) So it is treating \n as an expression and compiling the regex each time through (though I think modern perl may be smart enough to realize it is a constant expression and compile the regex only once). You would get the same behavior with this: split $arg, $data; if $arg contained '\n'. Of course, you _also_ get the same thing if you use a literal newline (either \n or if $arg contained a literal newline), because they function the same in a regex. In other words, it does not matter which you use because perl's interpolation of \n and the regex expansion of \n are identical: t hey both mean a newline. A more subtle example that shows what is going on is this: split '.', $data; If you feed that foo.bar.baz, it does not split it into three words; each character is a delimiter, because the dot is compiled to a regex. The new code looks better than the old one, but the log message may be improved. Agreed. I think the best explanation is something like: Perl's split function takes a regex pattern argument. You can also feed it an expression, which is then compiled into a regex at runtime. It therefore works to pass your pattern via single quotes, but it is much less obvious to a reader that the argument is meant to be a regex, not a static string. Using the traditional slash-delimiters makes this easier to read. -Peff -- To unsubscribe from this list: send the line unsubscribe git in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-remote-mediawiki: Fix a bug in a regexp
On Sat, Jun 8, 2013 at 9:35 AM, Célestin Matte
celestin.ma...@ensimag.fr wrote:
In Perl, '\n' is not a newline, but instead a literal backslash followed by an
n. As the output of rev-list --first-parent is line-oriented, what we want
here is a newline.
Signed-off-by: Célestin Matte celestin.ma...@ensimag.fr
Signed-off-by: Matthieu Moy matthieu@grenoble-inp.fr
---
contrib/mw-to-git/git-remote-mediawiki.perl |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/contrib/mw-to-git/git-remote-mediawiki.perl
b/contrib/mw-to-git/git-remote-mediawiki.perl
index 7af202f..a06bc31 100755
--- a/contrib/mw-to-git/git-remote-mediawiki.perl
+++ b/contrib/mw-to-git/git-remote-mediawiki.perl
@@ -1190,7 +1190,7 @@ sub mw_push_revision {
# history (linearized with --first-parent)
print STDERR Warning: no common ancestor, pushing complete
history\n;
my $history = run_git(rev-list --first-parent --children
$local);
- my @history = split('\n', $history);
+ my @history = split(/\n/, $history);
@history = @history[1..$#history];
foreach my $line (reverse @history) {
my @commit_info_split = split(/ |\n/, $line);
It would be quite acceptable to include this patch in your existing
patch series.
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Re: [PATCH] git-remote-mediawiki: Fix a bug in a regexp
On Sat, Jun 8, 2013 at 10:57 PM, Jeff King p...@peff.net wrote: On Sat, Jun 08, 2013 at 08:38:56PM +0200, Matthieu Moy wrote: Célestin Matte celestin.ma...@ensimag.fr writes: In Perl, '\n' is not a newline, but instead a literal backslash followed by an n. As the output of rev-list --first-parent is line-oriented, what we want here is a newline. This is right, but the code actually worked the way it was. I'm not sure, but my understanding is that '\n' is the string backslash followed by n, but interpreted as a regexp, it is a newline. Yes, the relevant doc (from perldoc -f split) is: The pattern /PATTERN/ may be replaced with an expression to specify patterns that vary at runtime. (To do runtime compilation only once, use /$variable/o.) So it is treating \n as an expression and compiling the regex each time through ... I read this as saying only that static /PATTERN/ can also be a composed /$PATTERN/. It does not indicate how string 'PATTERN' is treated, nor does any other part of perldoc -f split make special mention of string 'PATTERN'. In fact, the only explanation I found regarding string 'PATTERN' is in my Camel book (3rd edition, page 796) in a parenthesized comment: (... if you supply a string instead of a regular expression, it'll be interpreted as a regular expression anyway.) The new code looks better than the old one, but the log message may be improved. Agreed. I think the best explanation is something like: Perl's split function takes a regex pattern argument. You can also feed it an expression, which is then compiled into a regex at runtime. It therefore works to pass your pattern via single quotes, but it is much less obvious to a reader that the argument is meant to be a regex, not a static string. Using the traditional slash-delimiters makes this easier to read. Sounds good to me. -- To unsubscribe from this list: send the line unsubscribe git in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
