ls: always print "?" for allocated size of a dereferenced dangling symlink

Previously for `ls -Ls` (but not `ls -Lsl`), we referenced
the st_blocks returned from the previous failed stat() call.
This undefined value was seen to be 0 for dangling symlinks at least.
* src/ls.c (print_file_name_and_frills, length_of_file_name_and_frills):
Don't use st_blocks if the previous stat() failed
* tests/ls/dangle: Add a test case
* NEWS: Mention the fix, and roll up related items into a single entry.

1 files changed, 7 insertions, 5 deletions

diff --git a/src/ls.c b/src/ls.c
index 801e717c6..30df92c1a 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -4016,8 +4016,9 @@ print_file_name_and_frills (const struct fileinfo *f, size_t start_col)
 
   if (print_block_size)
     printf ("%*s ", format == with_commas ? 0 : block_size_width,
-            human_readable (ST_NBLOCKS (f->stat), buf, human_output_opts,
-                            ST_NBLOCKSIZE, output_block_size));
+            ! f->stat_ok ? "?"
+            : human_readable (ST_NBLOCKS (f->stat), buf, human_output_opts,
+                              ST_NBLOCKSIZE, output_block_size));
 
   if (print_scontext)
     printf ("%*s ", format == with_commas ? 0 : scontext_width, f->scontext);
@@ -4234,9 +4235,10 @@ length_of_file_name_and_frills (const struct fileinfo *f)
 
   if (print_block_size)
     len += 1 + (format == with_commas
-                ? strlen (human_readable (ST_NBLOCKS (f->stat), buf,
-                                          human_output_opts, ST_NBLOCKSIZE,
-                                          output_block_size))
+                ? strlen (! f->stat_ok ? "?"
+                          : human_readable (ST_NBLOCKS (f->stat), buf,
+                                            human_output_opts, ST_NBLOCKSIZE,
+                                            output_block_size))
                 : block_size_width);
 
   if (print_scontext)