Re: [Bug-tar] Previously existing files should not be an error when -k is specified

[Sergey Poznyakoff]

Jonathan Kamens <address@hidden> ha escrit:

>    If I specify -k to tell tar not to overwrite old files, and indeed
>    there are some old files that tar doesn't overwrite, then it prints
>    error messages about these files, which is wrong, and it exits with a
>    non-zero status, which is also wrong.

Thanks for reporting.  It is fixed in the repository.  Attached is a
patch against git HEAD.

Regards,
Sergey

* src/extract.c (maybe_recoverable): Return three-state value.
(extract_dir): Skip extraction if maybe_recoverable indicates so.
(extract_file): Likewise.
---
 src/extract.c |   52 ++++++++++++++++++++++++++++++++++++----------------
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/src/extract.c b/src/extract.c
index 6d70398..300f52b 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -486,17 +486,24 @@ file_newer_p (const char *file_name, struct tar_stat_info 
*tar_stat)
   return false;
 }
 
+#define RECOVER_NO 0
+#define RECOVER_OK 1
+#define RECOVER_SKIP 2
+
 /* Attempt repairing what went wrong with the extraction.  Delete an
    already existing file or create missing intermediate directories.
-   Return nonzero if we somewhat increased our chances at a successful
-   extraction.  errno is properly restored on zero return.  */
+   Return RECOVER_OK if we somewhat increased our chances at a successful
+   extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the
+   caller should skip extraction of that member.  The value of errno is
+   properly restored on returning RECOVER_NO.  */
+
 static int
 maybe_recoverable (char *file_name, int *interdir_made)
 {
   int e = errno;
 
   if (*interdir_made)
-    return 0;
+    return RECOVER_NO;
 
   switch (errno)
     {
@@ -506,13 +513,13 @@ maybe_recoverable (char *file_name, int *interdir_made)
       switch (old_files_option)
        {
        case KEEP_OLD_FILES:
-         return 0;
+         return RECOVER_SKIP;
 
        case KEEP_NEWER_FILES:
          if (file_newer_p (file_name, &current_stat_info))
            {
              errno = e;
-             return 0;
+             return RECOVER_NO;
            }
          /* FALL THROUGH */
 
@@ -522,7 +529,7 @@ maybe_recoverable (char *file_name, int *interdir_made)
          {
            int r = remove_any_file (file_name, ORDINARY_REMOVE_OPTION);
            errno = EEXIST;
-           return r;
+           return r > 0 ? RECOVER_OK : RECOVER_NO;
          }
 
        case UNLINK_FIRST_OLD_FILES:
@@ -534,15 +541,15 @@ maybe_recoverable (char *file_name, int *interdir_made)
       if (! make_directories (file_name))
        {
          errno = ENOENT;
-         return 0;
+         return RECOVER_NO;
        }
       *interdir_made = 1;
-      return 1;
+      return RECOVER_OK;
 
     default:
       /* Just say we can't do anything about it...  */
 
-      return 0;
+      return RECOVER_NO;
     }
 }
 
@@ -666,13 +673,21 @@ extract_dir (char *file_name, int typeflag)
          errno = EEXIST;
        }
 
-      if (maybe_recoverable (file_name, &interdir_made))
-       continue;
-
-      if (errno != EEXIST)
+      switch (maybe_recoverable (file_name, &interdir_made))
        {
-         mkdir_error (file_name);
-         return 1;
+       case RECOVER_OK:
+         continue;
+
+       case RECOVER_SKIP:
+         break;
+
+       case RECOVER_NO:
+         if (errno != EEXIST)
+           {
+             mkdir_error (file_name);
+             return 1;
+           }
+         break;
        }
       break;
     }
@@ -760,13 +775,18 @@ extract_file (char *file_name, int typeflag)
     }
   else
     {
+      int recover = RECOVER_NO;
       do
        fd = open_output_file (file_name, typeflag, mode ^ invert_permissions);
-      while (fd < 0 && maybe_recoverable (file_name, &interdir_made));
+      while (fd < 0
+            && (recover = maybe_recoverable (file_name, &interdir_made))
+                == RECOVER_OK);
 
       if (fd < 0)
        {
          skip_member ();
+         if (recover == RECOVER_SKIP)
+           return 0;
          open_error (file_name);
          return 1;
        }
-- 
1.6.0