Re: [Bug-tar] Symlink extraction broken w/recent CVS versions

[Sergey Poznyakoff]

Hello,

In the absence of a better solution, I have applied the following
patch:

2007-06-02  Sergey Poznyakoff  <address@hidden>

        * src/common.h (xform_type): New data type
        (transform_member_name): Last argument is of
        xform_type type. All callers updated

        * src/extract.c: Update calls to transform_member_name
        * src/list.c (decode_xform): Symbolic links are exempt from
        component stripping and name suffix normalization but subject to
        file name transformation proper.

This solution satisfies both the test case provided by MrC, and the
one submitted by Morten Welinder
(http://lists.gnu.org/archive/html/bug-tar/2007-03/msg00011.html).

Regards,
Sergey

Index: src/common.h
===================================================================
RCS file: /cvsroot/tar/tar/src/common.h,v
retrieving revision 1.97
diff -p -u -r1.97 common.h
--- src/common.h        19 May 2007 17:02:13 -0000      1.97
+++ src/common.h        1 Jun 2007 21:21:33 -0000
@@ -725,7 +725,14 @@ bool string_ascii_p (const char *str);
 bool utf8_convert (bool to_utf, char const *input, char **output);
 
 /* Module transform.c */
+typedef enum
+  {
+    xform_regfile,
+    xform_link,
+    xform_symlink
+  } xform_type;
+
 void set_transform_expr (const char *expr);
 bool transform_name (char **pinput);
-bool transform_member_name (char **pinput, bool lnk);
+bool transform_member_name (char **pinput, xform_type type);
 bool transform_name_fp (char **pinput, char *(*fun)(char *, void *), void *);
Index: src/extract.c
===================================================================
RCS file: /cvsroot/tar/tar/src/extract.c,v
retrieving revision 1.101
diff -p -u -r1.101 extract.c
--- src/extract.c       30 Mar 2007 19:18:10 -0000      1.101
+++ src/extract.c       1 Jun 2007 21:21:33 -0000
@@ -917,7 +917,7 @@ extract_link (char *file_name, int typef
   int interdir_made = 0;
   char const *link_name;
 
-  transform_member_name (&current_stat_info.link_name, true);
+  transform_member_name (&current_stat_info.link_name, xform_link);
   link_name = current_stat_info.link_name;
   
   if (! absolute_names_option && contains_dot_dot (link_name))
@@ -974,7 +974,7 @@ extract_symlink (char *file_name, int ty
   int status;
   int interdir_made = 0;
 
-  transform_member_name (&current_stat_info.link_name, true);
+  transform_member_name (&current_stat_info.link_name, xform_symlink);
 
   if (! absolute_names_option
       && (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name)
Index: src/list.c
===================================================================
RCS file: /cvsroot/tar/tar/src/list.c,v
retrieving revision 1.104
diff -p -u -r1.104 list.c
--- src/list.c  19 May 2007 17:03:28 -0000      1.104
+++ src/list.c  1 Jun 2007 21:21:33 -0000
@@ -472,9 +472,27 @@ read_header (bool raw_extended_headers)
 static char *
 decode_xform (char *file_name, void *data)
 {
-  bool link_target = *(bool*)data;
-  file_name = safer_name_suffix (file_name, link_target,
-                                absolute_names_option);
+  xform_type type = *(xform_type*)data;
+
+  switch (type)
+    {
+    case xform_symlink:
+      /* FIXME: It is not quite clear how and to which extent are the symbolic
+        links subject to filename transformation.  In the absence of another
+        solution, symbolic links are exempt from component stripping and
+        name suffix normalization, but subject to filename transformation
+        proper. */ 
+      return file_name;
+      
+    case xform_link:
+      file_name = safer_name_suffix (file_name, true, absolute_names_option);
+      break;
+      
+    case xform_regfile:
+      file_name = safer_name_suffix (file_name, false, absolute_names_option);
+      break;
+    }
+  
   if (strip_name_components)
     {
       size_t prefix_len = stripped_prefix_len (file_name,
@@ -487,9 +505,9 @@ decode_xform (char *file_name, void *dat
 }
 
 bool
-transform_member_name (char **pinput, bool lnk)
+transform_member_name (char **pinput, xform_type type)
 {
-  return transform_name_fp (pinput, decode_xform, &lnk);
+  return transform_name_fp (pinput, decode_xform, &type);
 }
 
 #define ISOCTAL(c) ((c)>='0'&&(c)<='7')
@@ -610,7 +628,7 @@ decode_header (union block *header, stru
        stat_info->is_dumpdir = true;
     }
 
-  transform_member_name (&stat_info->file_name, false);
+  transform_member_name (&stat_info->file_name, xform_regfile);
 }
 
 /* Convert buffer at WHERE0 of size DIGS from external format to