Re: [PATCH 2/1][BZ #866] glob() should match dangling symlinks.

[OndÅej BÃlka <neleai at seznam dot cz>]

On Thu, Oct 17, 2013 at 01:11:03PM -0400, Carlos O'Donell wrote:
> On 10/12/2013 04:25 AM, OndÅej BÃlka wrote:
> > Hi,
> > 
> > This is another bug in glob with patch in bugzilla from Tom Lee ready, 
> > see https://sourceware.org/bugzilla/show_bug.cgi?id=866
> > 
> > Patch itself is ok, what is left is decide if listing dangling symlinks
> > is desired behavior. 
> > 
> > Comments?
> 
> This patch looks good to me. We definitely want to match dangling 
> symlinks. I see that Rich agrees with me in #5 of the issue.
> 
> The goal here is to make glob match what the shell would do. 
> The shell should match dangling symlinks and so should glob.
> 
> The more interesting question is should we have some backwards
> compatibility for old programs? I would say no. It's a bug that
> we don't do exactly as the shell does and therefore the bug
> should be fixed for all users of the library.
> 
> However, this needs a testcase. It needs tst-gnuglob.c to be
> expanded to handle symlinks and then add a dangling symlink
> and show that we capture it in the glob. That shouldn't be too
> much more work since the infrastructure is all there.
>  
Actually this is tested by existing test that needs to be modified. 


diff --git a/posix/bug-glob1.c b/posix/bug-glob1.c
index 05c2da7..5baf0a1 100644
--- a/posix/bug-glob1.c
+++ b/posix/bug-glob1.c
@@ -60,15 +60,28 @@ do_test (void)
     }
   globfree (&gl);
 
+  strcpy (buf, fname);
+  buf[fnamelen] = '/';
+  buf[fnamelen + 1] = '\0';
+  e = glob (buf, 0, NULL, &gl);
+  if (e == 0)
+    {
+      printf ("glob(\"%s\") succeeded\n", buf);
+      retval = 1;
+    }
+  globfree (&gl);
+
+
+
   size_t fnamelen = strlen (fname);
   char buf[fnamelen + 2];
 
   strcpy (buf, fname);
   buf[fnamelen - 1] = '?';
   e = glob (buf, 0, NULL, &gl);
-  if (e == 0)
+  if (e != 0)
     {
-      printf ("glob(\"%s\") succeeded\n", buf);
+      printf ("glob(\"%s\") failed\n", buf);
       retval = 1;
     }
   globfree (&gl);
@@ -77,9 +90,9 @@ do_test (void)
   buf[fnamelen] = '*';
   buf[fnamelen + 1] = '\0';
   e = glob (buf, 0, NULL, &gl);
-  if (e == 0)
+  if (e != 0)
     {
-      printf ("glob(\"%s\") succeeded\n", buf);
+      printf ("glob(\"%s\") failed\n", buf);
       retval = 1;
     }
   globfree (&gl);
diff --git a/posix/glob.c b/posix/glob.c
index 85237c2..cd07c13 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -203,7 +203,7 @@ static const char *next_brace_sub (const char *begin, int flags) __THROWNL;
 
 static int glob_in_dir (const char *pattern, const char *directory,
 			int flags, int (*errfunc) (const char *, int),
-			glob_t *pglob, size_t alloca_used);
+			glob_t *pglob, size_t alloca_used, int chklnks);
 extern int __glob_pattern_type (const char *pattern, int quote)
     attribute_hidden;
 
@@ -1082,7 +1082,7 @@ glob (pattern, flags, errfunc, pglob)
 	  status = glob_in_dir (filename, dirs.gl_pathv[i],
 				((flags | GLOB_APPEND)
 				 & ~(GLOB_NOCHECK | GLOB_NOMAGIC)),
-				errfunc, pglob, alloca_used);
+				errfunc, pglob, alloca_used, 1);
 	  if (status == GLOB_NOMATCH)
 	    /* No matches in this directory.  Try the next.  */
 	    continue;
@@ -1189,7 +1189,7 @@ glob (pattern, flags, errfunc, pglob)
       if (dirname_modified)
 	flags &= ~(GLOB_NOCHECK | GLOB_NOMAGIC);
       status = glob_in_dir (filename, dirname, flags, errfunc, pglob,
-			    alloca_used);
+			    alloca_used, 0);
       if (status != 0)
 	{
 	  if (status == GLOB_NOMATCH && flags != orig_flags
@@ -1466,7 +1466,7 @@ link_exists2_p (const char *dir, size_t dirlen, const char *fname,
 static int
 glob_in_dir (const char *pattern, const char *directory, int flags,
 	     int (*errfunc) (const char *, int),
-	     glob_t *pglob, size_t alloca_used)
+	     glob_t *pglob, size_t alloca_used, int chklnks)
 {
   size_t dirlen = strlen (directory);
   void *stream = NULL;
@@ -1609,8 +1609,8 @@ glob_in_dir (const char *pattern, const char *directory, int flags,
 		  /* If the file we found is a symlink we have to
 		     make sure the target file exists.  */
 		  if (!DIRENT_MIGHT_BE_SYMLINK (d)
-		      || link_exists_p (dfd, directory, dirlen, name, pglob,
-					flags))
+		      || (chklnks ? link_exists_p (dfd, directory, dirlen, name, pglob,
+					flags) : 1))
 		    {
 		      if (cur == names->count)
 			{