ash: fix slash treatment in expmeta

Commit 549deab caused this sequence of commands:

   mkdir foo
   cd foo
   touch a b
   echo "./"*

to return './*' instead of the expected './a ./b'.  The problem
was caused by the backport of commit 880d952 from dash.  In dash
the issue was fixed by two further commits by Herbert Xu:

<d6d06ff> [EXPAND] Fixed non-leading slash treatment in expmeta
<36f0fa8> [EXPAND] Fix slash treatment in expmeta

(See git://git.kernel.org/pub/scm/utils/dash/dash.git)

Apply these fixes to BusyBox ash, thus causing the new test
glob3.tests to succeed.

function                                             old     new   delta
expmeta                                              469     528     +59

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 10 deletions

diff --git a/shell/ash.c b/shell/ash.c
index f6190c3e2..42c91257e 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6992,10 +6992,11 @@ expmeta(char *expdir, char *enddir, char *name)
         struct dirent *dp;
         int atend;
         int matchdot;
+        int esc;
 
         metaflag = 0;
         start = name;
-        for (p = name; *p; p++) {
+        for (p = name; esc = 0, *p; p += esc + 1) {
                 if (*p == '*' || *p == '?')
                         metaflag = 1;
                 else if (*p == '[') {
@@ -7012,15 +7013,16 @@ expmeta(char *expdir, char *enddir, char *name)
                                         break;
                                 }
                         }
-                } else if (*p == '\\')
-                        p++;
-                else if (*p == '/') {
-                        if (metaflag)
-                                goto out;
-                        start = p + 1;
+                } else {
+                        if (*p == '\\')
+                                esc++;
+                        if (p[esc] == '/') {
+                                if (metaflag)
+                                        break;
+                                start = p + esc + 1;
+                        }
                 }
         }
- out:
         if (metaflag == 0) {    /* we've reached the end of the file name */
                 if (enddir != expdir)
                         metaflag++;
@@ -7060,7 +7062,8 @@ expmeta(char *expdir, char *enddir, char *name)
                 atend = 1;
         } else {
                 atend = 0;
-                *endname++ = '\0';
+                *endname = '\0';
+                endname += esc + 1;
         }
         matchdot = 0;
         p = start;
@@ -7085,7 +7088,7 @@ expmeta(char *expdir, char *enddir, char *name)
         }
         closedir(dirp);
         if (!atend)
-                endname[-1] = '/';
+                endname[-esc - 1] = esc ? '\\' : '/';
 }
 
 static struct strlist *