debugedit mishandles empty DW_AT_comp_dir (Roland McGrath)

- fpc seems to produce DW_AT_comp_dir with value "" (empty string).
  This is dubious, but debugedit makes it even worse by getting confused by it.

1 files changed, 10 insertions, 5 deletions

diff --git a/tools/debugedit.c b/tools/debugedit.c
index 920624197..13ed1e132 100644
--- a/tools/debugedit.c
+++ b/tools/debugedit.c
@@ -560,11 +560,16 @@ edit_dwarf2_line (DSO *dso, uint_32 off, char *comp_dir, int phase)
 	}
       else
 	{
-	  memcpy (s, comp_dir, comp_dir_len);
-	  s[comp_dir_len] = '/';
-	  memcpy (s + comp_dir_len + 1, dirt[value], dir_len);
-	  s[comp_dir_len + 1 + dir_len] = '/';
-	  memcpy (s + comp_dir_len + 1 + dir_len + 1, file, file_len + 1);
+	  char *p = s;
+	  if (comp_dir_len != 0)
+	    {
+	      memcpy (s, comp_dir, comp_dir_len);
+	      s[comp_dir_len] = '/';
+	      p += comp_dir_len + 1;
+	    }
+	  memcpy (p, dirt[value], dir_len);
+	  p[dir_len] = '/';
+	  memcpy (p + dir_len + 1, file, file_len + 1);
 	}
       canonicalize_path (s, s);
       if (list_file_fd != -1)