[PATCH v2] help.c: help.autocorrect=prompt waits for user action

["Azeem Bande-Ali via GitGitGadget" <gitgitgadget@gmail.com>]

From: Azeem Bande-Ali <me@azeemba.com>

If help.autocorrect is set to 'prompt', the user is prompted
before the suggested action is executed.

Based on original patch by David Barr
https://lore.kernel.org/git/1283758030-13345-1-git-send-email-david.barr@cordelta.com/

Signed-off-by: Azeem Bande-Ali <me@azeemba.com>
---
    New config for help.autocorrect to prompt user before action
    
    Changes since v1:
    
     * Use bullet lists for documenting the various settings now supported
       by help.autoCorrect
     * Add a check for an interactive terminal early to bail if the user has
       the "prompt" setting
     * Make the output more compact so the user can see the suggestion and
       the prompt in one line.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1012%2Fazeemba%2Fautoprompt-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1012/azeemba/autoprompt-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1012

Range-diff vs v1:

 1:  7f72819b805 ! 1:  5819b872356 help.c: help.autocorrect=prompt waits for user action
     @@ Documentation/config/help.txt: help.format::
      -	is run immediately. If "never", suggestions are not shown at all. The
      -	default value is zero.
      +	to the error, git will try to suggest the correct command or even
     -+	run the intended command.
     -+	If this config value is 0, then the suggested command will be shown.
     -+	If it is positive, the suggested command will automatically
     -+	run after waiting for that many deciseconds (0.1 sec).
     -+	If it is "immediate", the suggested command will be
     -+	run immediately.
     -+	If it is "prompt", then the user will be shown the
     -+	suggestion and will be prompted for confirmation before the command
     -+	is run.
     -+	If it is "never", then no suggestion will be shown and no command
     -+	will be run.
     -+	0 is the default value for this config.
     ++	run the suggestion automatically. Possible config values are:
     ++	 - 0 (default): show the suggested command.
     ++	 - positive number: run the suggested command after specified
     ++deciseconds (0.1 sec).
     ++	 - "immediate": run the suggested command immediately.
     ++	 - "prompt": show the suggestion and prompt for confirmation to run
     ++the command.
     ++	 - "never": don't run or show any suggested command.
       
       help.htmlPath::
       	Specify the path where the HTML documentation resides. File system paths
     @@ help.c: static int git_unknown_cmd_config(const char *var, const char *value, vo
       			int v = git_config_int(var, value);
       			autocorrect = (v < 0)
      @@ help.c: const char *help_unknown_cmd(const char *cmd)
     + 
     + 	read_early_config(git_unknown_cmd_config, NULL);
     + 
     ++	/*
     ++	 * Disable autocorrection prompt in a non-interactive session
     ++	 */
     ++	if ((autocorrect == AUTOCORRECT_PROMPT) && (!isatty(0) || !isatty(2)))
     ++		autocorrect = AUTOCORRECT_NEVER;
     ++
     + 	if (autocorrect == AUTOCORRECT_NEVER) {
     + 		fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
     + 		exit(1);
     +@@ help.c: const char *help_unknown_cmd(const char *cmd)
       				   _("Continuing under the assumption that "
       				     "you meant '%s'."),
       				   assumed);
      -		else {
      +		else if (autocorrect == AUTOCORRECT_PROMPT) {
     -+			if (!isatty(STDIN_FILENO) | !isatty(STDERR_FILENO))
     -+				exit(1);
     -+
     -+			char *answer;
     -+			fprintf_ln(stderr, _("Assuming you meant: '%s'."),
     -+				   assumed);
     -+			answer = git_prompt(_("Continue? (y/N)"), PROMPT_ECHO);
     ++			char* answer;
     ++			struct strbuf msg = STRBUF_INIT;
     ++			strbuf_addf(&msg, _("Run '%s' instead? (y/N)"),
     ++				    assumed);
     ++			answer = git_prompt(msg.buf, PROMPT_ECHO);
     ++			strbuf_release(&msg);
      +			if (!(starts_with(answer, "y") ||
      +			      starts_with(answer, "Y")))
      +				exit(1);


 Documentation/config/help.txt | 16 +++++++++-------
 help.c                        | 22 +++++++++++++++++++++-
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/Documentation/config/help.txt b/Documentation/config/help.txt
index 783a90a0f93..610701f9a37 100644
--- a/Documentation/config/help.txt
+++ b/Documentation/config/help.txt
@@ -9,13 +9,15 @@ help.format::
 
 help.autoCorrect::
 	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.
+	to the error, git will try to suggest the correct command or even
+	run the suggestion automatically. Possible config values are:
+	 - 0 (default): show the suggested command.
+	 - positive number: run the suggested command after specified
+deciseconds (0.1 sec).
+	 - "immediate": run the suggested command immediately.
+	 - "prompt": show the suggestion and prompt for confirmation to run
+the command.
+	 - "never": don't run or show any suggested command.
 
 help.htmlPath::
 	Specify the path where the HTML documentation resides. File system paths
diff --git a/help.c b/help.c
index 3c3bdec2135..22bb05e8e3d 100644
--- a/help.c
+++ b/help.c
@@ -11,6 +11,7 @@
 #include "version.h"
 #include "refs.h"
 #include "parse-options.h"
+#include "prompt.h"
 
 struct category_description {
 	uint32_t category;
@@ -472,6 +473,7 @@ int is_in_cmdlist(struct cmdnames *c, const char *s)
 static int autocorrect;
 static struct cmdnames aliases;
 
+#define AUTOCORRECT_PROMPT (-3)
 #define AUTOCORRECT_NEVER (-2)
 #define AUTOCORRECT_IMMEDIATELY (-1)
 
@@ -486,6 +488,8 @@ static int git_unknown_cmd_config(const char *var, const char *value, void *cb)
 			autocorrect = AUTOCORRECT_NEVER;
 		} else if (!strcmp(value, "immediate")) {
 			autocorrect = AUTOCORRECT_IMMEDIATELY;
+		} else if (!strcmp(value, "prompt")) {
+			autocorrect = AUTOCORRECT_PROMPT;
 		} else {
 			int v = git_config_int(var, value);
 			autocorrect = (v < 0)
@@ -539,6 +543,12 @@ const char *help_unknown_cmd(const char *cmd)
 
 	read_early_config(git_unknown_cmd_config, NULL);
 
+	/*
+	 * Disable autocorrection prompt in a non-interactive session
+	 */
+	if ((autocorrect == AUTOCORRECT_PROMPT) && (!isatty(0) || !isatty(2)))
+		autocorrect = AUTOCORRECT_NEVER;
+
 	if (autocorrect == AUTOCORRECT_NEVER) {
 		fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
 		exit(1);
@@ -618,7 +628,17 @@ const char *help_unknown_cmd(const char *cmd)
 				   _("Continuing under the assumption that "
 				     "you meant '%s'."),
 				   assumed);
-		else {
+		else if (autocorrect == AUTOCORRECT_PROMPT) {
+			char* answer;
+			struct strbuf msg = STRBUF_INIT;
+			strbuf_addf(&msg, _("Run '%s' instead? (y/N)"),
+				    assumed);
+			answer = git_prompt(msg.buf, PROMPT_ECHO);
+			strbuf_release(&msg);
+			if (!(starts_with(answer, "y") ||
+			      starts_with(answer, "Y")))
+				exit(1);
+		} else {
 			fprintf_ln(stderr,
 				   _("Continuing in %0.1f seconds, "
 				     "assuming that you meant '%s'."),

base-commit: 2d755dfac9aadab25c3e025b849252b8c0a61465
-- 
gitgitgadget