[PATCH] vi: POSIX backslashes in expand_args

vi: POSIX backslashes in expand_args

The previous behaviour treated every backslash as escaping a character,
rather than following POSIX, which only removes backslashes where they
are escaping a special character.

And so only one backslash is lost when having a chain of backslashes
with a percent sign at the end. (plus any shell handling of backslashes
in unquoted arguments)

Signed-off-by: Morgan Bartlett <[email protected]>

diff --git a/editors/vi.c b/editors/vi.c
index ba607bcfd..d91a4a504 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2696,7 +2696,9 @@ static char *expand_args(char *args)
 		} else if (*s == '#') {
 			replace = alt_filename;
 		} else {
-			if (*s == '\\' && s[1] != '\0') {
+			/* According to POSIX, backslash-escapes are ignored
unless they
+			 * escape a special character. It gives an example
of \\% expanding to \% */
+			if (*s == '\\' && (s[1] == '%' || s[1] == '#')) {
 				char *t;
 				for (t = s; *t; t++)
 					*t = t[1];