[git commit] libbb/lineedit: do not escape %^=+}]:, escape ~? in tab completion

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=6d2463ac01dd88cc4359ebbeae9cd757ce037c2b
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
.rodata                                           104185  104180      -5

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 libbb/lineedit.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 68d19e127..e8d721e61 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1133,7 +1133,16 @@ static void showfiles(void)
 
 static const char *is_special_char(char c)
 {
-	return strchr(" `\"#$%^&*()=+{}[]:;'|\\<>", c);
+	// {: It's mandatory to escape { only if entire name is "{"
+	// (otherwise it's not special. Example: file named "{ "
+	// can be escaped simply as "{\ "; "{a" or "a{" need no escaping),
+	// or if shell supports brace expansion
+	// (ash doesn't, hush optionally does).
+	// (): unlike {, shell treats () specially even in contexts
+	// where they clearly are not valid (e.g. "echo )" is an error).
+	// #: needs escaping to not start a shell comment.
+	return strchr(" `'\"\\#$~?*[{()&;|<>", c);
+	// Used to also have %^=+}]: but not necessary to escape?
 }
 
 static char *quote_special_chars(char *found)