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

function                                             old     new   delta
.rodata                                           104185  104180      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 1 deletions

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)