# [PATCH] gittrack.sh accepts invalid branch names 4 messages from 2005-04-20 to 2005-04-21. Participants: Pavel Roskin, Petr Baudis, Paul Jackson. Thread: https://gitlist.dev/t/176 ## Pavel Roskin, 2005-04-20 19:48 Subject: [PATCH] gittrack.sh accepts invalid branch names Message-ID: <1114026510.15186.15.camel@dv> URL: https://gitlist.dev/e/1114026510.15186.15.camel%40dv ``` Hello, Petr and everybody! gittrack.sh allows abbreviated branch names, e.g. it's possible to run "git track lin" when there is a branch called "linus". I believe it's a bug, not a feature. Please look at this line from gittrack.sh: grep -q $(echo -e "^$name\t" | sed 's/\./\\./g') .git/remotes The result of command expansion is subjected to word splitting, which means the trailing tab is removed as a space. So grep doesn't see the tab. The way to avoid word splitting would be to quote "$()", but it would make the shell code too hairy. I'm not even sure all shells would interpret "$("$name")" correctly. So I decided to use tab directly in the sed expression. I cannot think of any portable way to avoid grep completely ("q" is a GNU sed extension, and we want to support BSD, I think), so it's still there, looking for any output from sed. Signed-off-by: Pavel Roskin --- a/gittrack.sh +++ b/gittrack.sh @@ -35,7 +35,7 @@ die () { mkdir -p .git/heads if [ "$name" ]; then - grep -q $(echo -e "^$name\t" | sed 's/\./\\./g') .git/remotes || \ + sed -ne "/^$name\t/p" .git/remotes | grep -q . || \ [ -s ".git/heads/$name" ] || \ die "unknown branch \"$name\"" -- Regards, Pavel Roskin ``` ## Petr Baudis, 2005-04-20 23:21 Subject: Re: [PATCH] gittrack.sh accepts invalid branch names Message-ID: <20050420232110.GA12962@pasky.ji.cz> URL: https://gitlist.dev/e/20050420232110.GA12962%40pasky.ji.cz In-Reply-To: <1114026510.15186.15.camel@dv> ``` Dear diary, on Wed, Apr 20, 2005 at 09:48:30PM CEST, I got a letter where Pavel Roskin told me that... > --- a/gittrack.sh > +++ b/gittrack.sh > @@ -35,7 +35,7 @@ die () { > mkdir -p .git/heads > > if [ "$name" ]; then > - grep -q $(echo -e "^$name\t" | sed 's/\./\\./g') .git/remotes || \ > + sed -ne "/^$name\t/p" .git/remotes | grep -q . || \ > [ -s ".git/heads/$name" ] || \ > die "unknown branch \"$name\"" This fixes the acceptance, but not the choice. What does the grep -q . exactly do? Just sets error code based on whether the sed output is non-empty? What about [] instead? -- Petr "Pasky" Baudis Stuff: http://pasky.or.cz/ C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor ``` ## Paul Jackson, 2005-04-20 23:22 Subject: Re: [PATCH] gittrack.sh accepts invalid branch names Message-ID: <20050420162234.3ccbf23e.pj@sgi.com> URL: https://gitlist.dev/e/20050420162234.3ccbf23e.pj%40sgi.com In-Reply-To: <1114026510.15186.15.camel@dv> ``` Pavel wrote: > sed -ne "/^$name\t/p" .git/remotes | grep -q . Consider using the following to look for a match of $name with the first tab separated field of the remotes file (and to avoid using 'grep -q', which is not in all grep's, so far as I know): cut -f1 .git/remotes | grep -Fx "$name" >/dev/null -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373, 1.925.600.0401 ``` ## Pavel Roskin, 2005-04-21 01:28 Subject: Re: [PATCH] gittrack.sh accepts invalid branch names Message-ID: <1114046931.20044.11.camel@dv> URL: https://gitlist.dev/e/1114046931.20044.11.camel%40dv In-Reply-To: <20050420232110.GA12962@pasky.ji.cz> ``` Hi, Petr! On Thu, 2005-04-21 at 01:21 +0200, Petr Baudis wrote: > Dear diary, on Wed, Apr 20, 2005 at 09:48:30PM CEST, I got a letter > where Pavel Roskin told me that... > > --- a/gittrack.sh > > +++ b/gittrack.sh > > @@ -35,7 +35,7 @@ die () { > > mkdir -p .git/heads > > > > if [ "$name" ]; then > > - grep -q $(echo -e "^$name\t" | sed 's/\./\\./g') .git/remotes || \ > > + sed -ne "/^$name\t/p" .git/remotes | grep -q . || \ > > [ -s ".git/heads/$name" ] || \ > > die "unknown branch \"$name\"" > > This fixes the acceptance, but not the choice. > > What does the grep -q . exactly do? Just sets error code based on > whether the sed output is non-empty? Yes. > What about [] instead? You'll need another pair of quotes for that: [ "$(sed -ne "/^$name\t/p" .git/remotes)" ]; echo $? If I remember correctly from my Autoconf hacking experience, not all shells like mixing quotes and command substitution, and even bash treated this differently in different versions. I can do more research, but it seems just too fragile to me. Another thing I remember is that "case" would not need quotes. For some historic reasons, the expression between "case" and "in" is subjected to command substitution, but not word expansion. So the patch becomes: --- a/gittrack.sh +++ b/gittrack.sh @@ -35,9 +35,11 @@ die () { mkdir -p .git/heads if [ "$name" ]; then - grep -q $(echo -e "^$name\t" | sed 's/\./\\./g') .git/remotes || \ + case x$(sed -ne "/^$name\t/p" .git/remotes) in + x) [ -s ".git/heads/$name" ] || \ - die "unknown branch \"$name\"" + die "unknown branch \"$name\"" ;; + esac echo $name >.git/tracking Looks rather ugly for my taste, but just in case: Signed-off-by: Pavel Roskin By the way, please check all references to .git/remotes - this bug is not specific to gittrack.sh. -- Regards, Pavel Roskin ```