[U-Boot] [RFC PATCH 1/4] common: command: Fix command auto-completion

[Boris Brezillon <boris.brezillon@bootlin.com>]

When auto-completing command arguments, the last argument is not
necessarily the one we need to auto-complete. When the last character is
a space, a tab or '\0' what we want instead is list all possible values,
or if there's only one possible value, place this value on the command
line instead of trying to suffix the last valid argument with missing
chars.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
 common/command.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/common/command.c b/common/command.c
index 2433a89e0a8e..435824356b50 100644
--- a/common/command.c
+++ b/common/command.c
@@ -362,13 +362,21 @@ int cmd_auto_complete(const char *const prompt, char *buf, int *np, int *colp)
 	sep = NULL;
 	seplen = 0;
 	if (i == 1) { /* one match; perfect */
-		k = strlen(argv[argc - 1]);
+		if (last_char != '\0' && !isblank(last_char))
+			k = strlen(argv[argc - 1]);
+		else
+			k = 0;
+
 		s = cmdv[0] + k;
 		len = strlen(s);
 		sep = " ";
 		seplen = 1;
 	} else if (i > 1 && (j = find_common_prefix(cmdv)) != 0) { /* more */
-		k = strlen(argv[argc - 1]);
+		if (last_char != '\0' && !isblank(last_char))
+			k = strlen(argv[argc - 1]);
+		else
+			k = 0;
+
 		j -= k;
 		if (j > 0) {
 			s = cmdv[0] + k;
-- 
2.17.1