Merge branch 'dd/help-autocorrect-never'

"git $cmd $args", when $cmd is not a recognised subcommand, by
default tries to see if $cmd is a typo of an existing subcommand
and optionally executes the corrected command if there is only one
possibility, depending on the setting of help.autocorrect; the
users can now disable the whole thing, including the cycles spent
to find a likely typo, by setting the configuration variable to
'never'.

* dd/help-autocorrect-never:
  help.c: help.autocorrect=never means "do not compute suggestions"

Documentation/config/help.txt

@@ -8,13 +8,14 @@ help.format::
 	the default. 'web' and 'html' are the same.
 
 help.autoCorrect::
-	Automatically correct and execute mistyped commands after
-	waiting for the given number of deciseconds (0.1 sec). If more
-	than one command can be deduced from the entered text, nothing
-	will be executed.  If the value of this option is negative,
-	the corrected command will be executed immediately. If the
-	value is 0 - the command will be just shown but not executed.
-	This is the default.
+	If git detects typos and can identify exactly one valid command similar
+	to the error, git will automatically run the intended command after
+	waiting a duration of time defined by this configuration value in
+	deciseconds (0.1 sec).  If this value is 0, the suggested corrections
+	will be shown, but not executed. If it is a negative integer, or
+	"immediate", the suggested command
+	is run immediately. If "never", suggestions are not shown at all. The
+	default value is zero.
 
 help.htmlPath::
 	Specify the path where the HTML documentation resides. File system paths

help.c

@@ -472,12 +472,26 @@ int is_in_cmdlist(struct cmdnames *c, const char *s)
 static int autocorrect;
 static struct cmdnames aliases;
 
+#define AUTOCORRECT_NEVER (-2)
+#define AUTOCORRECT_IMMEDIATELY (-1)
+
 static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 {
 	const char *p;
 
-	if (!strcmp(var, "help.autocorrect"))
-		autocorrect = git_config_int(var,value);
+	if (!strcmp(var, "help.autocorrect")) {
+		if (!value)
+			return config_error_nonbool(var);
+		if (!strcmp(value, "never")) {
+			autocorrect = AUTOCORRECT_NEVER;
+		} else if (!strcmp(value, "immediate")) {
+			autocorrect = AUTOCORRECT_IMMEDIATELY;
+		} else {
+			int v = git_config_int(var, value);
+			autocorrect = (v < 0)
+				? AUTOCORRECT_IMMEDIATELY : v;
+		}
+	}
 	/* Also use aliases for command lookup */
 	if (skip_prefix(var, "alias.", &p))
 		add_cmdname(&aliases, p, strlen(p));
@@ -525,6 +539,11 @@ const char *help_unknown_cmd(const char *cmd)
 
 	read_early_config(git_unknown_cmd_config, NULL);
 
+	if (autocorrect == AUTOCORRECT_NEVER) {
+		fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
+		exit(1);
+	}
+
 	load_command_list("git-", &main_cmds, &other_cmds);
 
 	add_cmd_list(&main_cmds, &aliases);
@@ -594,7 +613,7 @@ const char *help_unknown_cmd(const char *cmd)
 			   _("WARNING: You called a Git command named '%s', "
 			     "which does not exist."),
 			   cmd);
-		if (autocorrect < 0)
+		if (autocorrect == AUTOCORRECT_IMMEDIATELY)
 			fprintf_ln(stderr,
 				   _("Continuing under the assumption that "
 				     "you meant '%s'."),

t/t9003-help-autocorrect.sh

@@ -37,16 +37,30 @@ test_expect_success 'autocorrect showing candidates' '
 	grep "^	distimdistim" actual
 '
 
-test_expect_success 'autocorrect running commands' '
-	git config help.autocorrect -1 &&
+for immediate in -1 immediate
+do
+	test_expect_success 'autocorrect running commands' '
+		git config help.autocorrect $immediate &&
 
-	git lfg >actual &&
-	echo "a single log entry" >expect &&
-	test_cmp expect actual &&
+		git lfg >actual &&
+		echo "a single log entry" >expect &&
+		test_cmp expect actual &&
 
-	git distimdist >actual &&
-	echo "distimdistim was called" >expect &&
-	test_cmp expect actual
+		git distimdist >actual &&
+		echo "distimdistim was called" >expect &&
+		test_cmp expect actual
+	'
+done
+
+test_expect_success 'autocorrect can be declined altogether' '
+	git config help.autocorrect never &&
+
+	test_must_fail git lfg 2>actual &&
+	if test_have_prereq C_LOCALE_OUTPUT
+	then
+		grep "is not a git command" actual &&
+		test_line_count = 1 actual
+	fi
 '
 
 test_done