Re: Implementing branch attributes in git config

From: Linus Torvalds <torvalds@osdl.org>
Date: May 9, 2006, 19:24 UTC
Message-ID: <Pine.LNX.4.64.0605091215340.3718@g5.osdl.org>
In-Reply-To: <7vzmhr3wje.fsf@assigned-by-dhcp.cox.net>

On Tue, 9 May 2006, Junio C Hamano wrote:

Show 8 quoted lines

> 
> If we are shooting for "let's not do this again", I do not think
> (4) without some quoting convention is good enough.  Today, we
> are talking about branch names so we could give them artificial
> limits, which could be weaker than what we already have on the
> branch names, but we would later regret that, when we start
> wanting to have other names in the configuration (e.g. people's
> names).

Here's my suggestion as a patch.

NOTE! This patch could be applied right now, and to all the branches (to make 1.x, 1.2.x and 1.3.x all support the _syntax_). Even if nothing actually uses it.

It just makes the syntax be

	[section<space>+"<randomstring>"]

where the only rule for "randomstring" is that it can't contain a newline, and if you really want to insert a double-quote, you do it with \".

It turns that into the section name "secion.randomstring".

So you could use this for things like

	[email "torvalds@osdl.org"]
		name = Linus Torvalds

if you wanted to do the "email->name" conversion as part of the config file format (I'm not claiming that is sensible, I'm just giving it as an insane example). That would show up as the association

	email.torvalds@osdl.org.name -> Linus Torvalds

which is easy to parse (the "." in the email _looks_ ambiguous, but it isn't: you know that there will always be a single key-name, so you find the key name with "strrchr(name, '.')" and things are entirely unambiguous).

Now, it doesn't do any repo-config stuff, since the whole point of this is to make this a legal syntax, not actually start _using_ it yet. If people think this is an acceptable syntax, then pls apply to everything, and worry about usage later.

		Linus

---

diff --git a/config.c b/config.c
index 0f518c9..f3b74e0 100644
--- a/config.c
+++ b/config.c
@@ -134,6 +134,41 @@ static int get_value(config_fn_t fn, cha
 	return fn(name, value);
 }
 
+static int get_extended_base_var(char *name, int baselen, int c)
+{
+	do {
+		if (c == '\n')
+			return -1;
+		c = get_next_char();
+	} while (isspace(c));
+
+	/* We require the format to be '[base "extension"]' */
+	if (c != '"')
+		return -1;
+	name[baselen++] = '.';
+
+	for (;;) {
+		int c = get_next_char();
+		if (c == '\n')
+			return -1;
+		if (c == '"')
+			break;
+		if (c == '\\') {
+			c = get_next_char();
+			if (c == '\n')
+				return -1;
+		}
+		name[baselen++] = c;
+		if (baselen > MAXNAME / 2)
+			return -1;
+	}
+
+	/* Final ']' */
+	if (get_next_char() != ']')
+		return -1;
+	return baselen;
+}
+
 static int get_base_var(char *name)
 {
 	int baselen = 0;
@@ -144,6 +179,8 @@ static int get_base_var(char *name)
 			return -1;
 		if (c == ']')
 			return baselen;
+		if (isspace(c))
+			return get_extended_base_var(name, baselen, c);
 		if (!isalnum(c) && c != '.')
 			return -1;
 		if (baselen > MAXNAME / 2)