[v3,5/8] config: add --fixed-value option, un-implemented

Commit Message

Derrick Stolee Nov. 25, 2020, 10:12 p.m. UTC

From: Derrick Stolee <[e-mail]>

The 'git config' builtin takes a 'value-pattern' parameter for several
actions. This can cause confusion when expecting exact value matches
instead of regex matches, especially when the input string contains
metacharacters. While callers can escape the patterns themselves, it
would be more friendly to allow an argument to disable the pattern
matching in favor of an exact string match.

Add a new '--fixed-value' option that does not currently change the
behavior. The implementation will be filled in by later changes for
each appropriate action. For now, check and test that --fixed-value
will abort the command when included with an incompatible action or
without a 'value-pattern' argument.

The name '--fixed-value' was chosen over something simpler like
'--fixed' because some commands allow regular expressions on the
key in addition to the value.

Signed-off-by: Derrick Stolee <[e-mail]>
---
 Documentation/git-config.txt | 20 +++++++++++++-------
 builtin/config.c             | 36 ++++++++++++++++++++++++++++++++++++
 t/t1300-config.sh            | 24 ++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 7 deletions(-)

Comments

Eric Sunshine Nov. 25, 2020, 11:04 p.m. UTC | #1

On Wed, Nov 25, 2020 at 5:13 PM Derrick Stolee via GitGitGadget
<[e-mail]> wrote:
> [...]
> Add a new '--fixed-value' option that does not currently change the
> behavior. The implementation will be filled in by later changes for
> each appropriate action. For now, check and test that --fixed-value
> will abort the command when included with an incompatible action or
> without a 'value-pattern' argument.
> [...]
> Signed-off-by: Derrick Stolee <[e-mail]>
> ---
> diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
> @@ -9,15 +9,15 @@ git-config - Get and set repository or global options
> +'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] --get name [value-pattern]
> +'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] --get-all name [value-pattern]
> +'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] [--name-only] --get-regexp name_regex [value-pattern]

Didn't notice this before (since I wasn't paying close attention), but
portions of the command which are to be filled-in by the user are
normally surrounded by angle brackets. Without the angle brackets, the
interpretation is that the argument is to be typed literally as shown.
So, the above should really be <value-pattern> and <name_regex> (or
even better <name-regex>), just as other fill-in arguments
<file-option> and <type> are formatted already.

I'm not suggesting that this series should tackle such a change since
that would be straying quite far from the original goal (which, as I
recall, was fixing a misbehavior of git-maintenance), but just
pointing out a possible mini-project for someone to tackle at some
point.

> +--fixed-value::
> +       When used with the `value-pattern` argument, treat `value-pattern` as
> +       an exact string instead of a regular expression. This will restrict
> +       the name/value pairs that are matched to only those where the value
> +       is exactly equal to the `value-pattern`.

Likewise, this would also use the angle brackets as `<value-pattern>`
(or '<value-pattern>' with single quotes rather than backquotes, for
which, I believe, Junio recently stated his preference)...

>  --type <type>::
>    'git config' will ensure that any input or output is valid under the given
>    type constraint(s), and will canonicalize outgoing values in `<type>`'s

... just like <type> is shown in angle brackets.

> +       OPT_BOOL(0, "fixed-value", &fixed_value, N_("use string equality when comparing values to 'value-pattern'")),

Here, I think omitting angle brackets is common, so this is probably okay.

Patch

diff --git a/Documentation/git-config.txt b/Documentation/git-config.txt
index 0be5499952..09a1d273a9 100644
--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt
@@ -9,15 +9,15 @@  git-config - Get and set repository or global options
 SYNOPSIS
 --------
 [verse]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] name [value [value-pattern]]
+'git config' [<file-option>] [--type=<type>] [--fixed-value] [--show-origin] [--show-scope] [-z|--null] name [value [value-pattern]]
 'git config' [<file-option>] [--type=<type>] --add name value
-'git config' [<file-option>] [--type=<type>] --replace-all name value [value-pattern]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] --get name [value-pattern]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] --get-all name [value-pattern]
-'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--name-only] --get-regexp name_regex [value-pattern]
+'git config' [<file-option>] [--type=<type>] [--fixed-value] --replace-all name value [value-pattern]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] --get name [value-pattern]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] --get-all name [value-pattern]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [--show-scope] [-z|--null] [--fixed-value] [--name-only] --get-regexp name_regex [value-pattern]
 'git config' [<file-option>] [--type=<type>] [-z|--null] --get-urlmatch name URL
-'git config' [<file-option>] --unset name [value-pattern]
-'git config' [<file-option>] --unset-all name [value-pattern]
+'git config' [<file-option>] [--fixed-value] --unset name [value-pattern]
+'git config' [<file-option>] [--fixed-value] --unset-all name [value-pattern]
 'git config' [<file-option>] --rename-section old_name new_name
 'git config' [<file-option>] --remove-section name
 'git config' [<file-option>] [--show-origin] [--show-scope] [-z|--null] [--name-only] -l | --list
@@ -165,6 +165,12 @@  See also <<FILES>>.
 --list::
 	List all variables set in config file, along with their values.
 
+--fixed-value::
+	When used with the `value-pattern` argument, treat `value-pattern` as
+	an exact string instead of a regular expression. This will restrict
+	the name/value pairs that are matched to only those where the value
+	is exactly equal to the `value-pattern`.
+
 --type <type>::
   'git config' will ensure that any input or output is valid under the given
   type constraint(s), and will canonicalize outgoing values in `<type>`'s
diff --git a/builtin/config.c b/builtin/config.c
index 9d97091561..d0adbed872 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -34,6 +34,7 @@  static int respect_includes_opt = -1;
 static struct config_options config_options;
 static int show_origin;
 static int show_scope;
+static int fixed_value;
 
 #define ACTION_GET (1<<0)
 #define ACTION_GET_ALL (1<<1)
@@ -141,6 +142,7 @@  static struct option builtin_config_options[] = {
 	OPT_BIT(0, "rename-section", &actions, N_("rename section: old-name new-name"), ACTION_RENAME_SECTION),
 	OPT_BIT(0, "remove-section", &actions, N_("remove a section: name"), ACTION_REMOVE_SECTION),
 	OPT_BIT('l', "list", &actions, N_("list all"), ACTION_LIST),
+	OPT_BOOL(0, "fixed-value", &fixed_value, N_("use string equality when comparing values to 'value-pattern'")),
 	OPT_BIT('e', "edit", &actions, N_("open an editor"), ACTION_EDIT),
 	OPT_BIT(0, "get-color", &actions, N_("find the color configured: slot [default]"), ACTION_GET_COLOR),
 	OPT_BIT(0, "get-colorbool", &actions, N_("find the color setting: slot [stdout-is-tty]"), ACTION_GET_COLORBOOL),
@@ -745,6 +747,40 @@  int cmd_config(int argc, const char **argv, const char *prefix)
 		usage_builtin_config();
 	}
 
+	/* check usage of --fixed-value */
+	if (fixed_value) {
+		int allowed_usage = 0;
+
+		switch (actions) {
+		/* git config --get <name> <value-pattern> */
+		case ACTION_GET:
+		/* git config --get-all <name> <value-pattern> */
+		case ACTION_GET_ALL:
+		/* git config --get-regexp <name-pattern> <value-pattern> */
+		case ACTION_GET_REGEXP:
+		/* git config --unset <name> <value-pattern> */
+		case ACTION_UNSET:
+		/* git config --unset-all <name> <value-pattern> */
+		case ACTION_UNSET_ALL:
+			allowed_usage = argc > 1 && !!argv[1];
+			break;
+
+		/* git config <name> <value> <value-pattern> */
+		case ACTION_SET_ALL:
+		/* git config --replace-all <name> <value> <value-pattern> */
+		case ACTION_REPLACE_ALL:
+			allowed_usage = argc > 2 && !!argv[2];
+			break;
+
+		/* other options don't allow --fixed-value */
+		}
+
+		if (!allowed_usage) {
+			error(_("--fixed-value only applies with 'value-pattern'"));
+			usage_builtin_config();
+		}
+	}
+
 	if (actions & PAGING_ACTIONS)
 		setup_auto_pager("config", 1);
 
diff --git a/t/t1300-config.sh b/t/t1300-config.sh
index 040b9f7506..f6f071006d 100755
--- a/t/t1300-config.sh
+++ b/t/t1300-config.sh
@@ -1967,4 +1967,28 @@  test_expect_success '--replace-all and value-pattern' '
 	test_cmp expect actual
 '
 
+test_expect_success 'refuse --fixed-value for incompatible actions' '
+	test_when_finished rm -f config &&
+	git config --file=config dev.null bogus &&
+
+	# These modes do not allow --fixed-value at all
+	test_must_fail git config --file=config --fixed-value --add dev.null bogus &&
+	test_must_fail git config --file=config --fixed-value --get-urlmatch dev.null bogus &&
+	test_must_fail git config --file=config --fixed-value --get-urlmatch dev.null bogus &&
+	test_must_fail git config --file=config --fixed-value --rename-section dev null &&
+	test_must_fail git config --file=config --fixed-value --remove-section dev &&
+	test_must_fail git config --file=config --fixed-value --list &&
+	test_must_fail git config --file=config --fixed-value --get-color dev.null &&
+	test_must_fail git config --file=config --fixed-value --get-colorbool dev.null &&
+
+	# These modes complain when --fixed-value has no value-pattern
+	test_must_fail git config --file=config --fixed-value dev.null bogus &&
+	test_must_fail git config --file=config --fixed-value --replace-all dev.null bogus &&
+	test_must_fail git config --file=config --fixed-value --get dev.null &&
+	test_must_fail git config --file=config --fixed-value --get-all dev.null &&
+	test_must_fail git config --file=config --fixed-value --get-regexp "dev.*" &&
+	test_must_fail git config --file=config --fixed-value --unset dev.null &&
+	test_must_fail git config --file=config --fixed-value --unset-all dev.null
+'
+
 test_done