[8.18] (backport #18091) Preserve mtime explicitly when creating tar artifacts (#18109)

* Preserve mtime explicitly when creating tar artifacts (#18091)

* Preserve mtime explicitly when creating tar artifacts

When building tar archives, explicitly set mtime. This avoids losing that
information in the minitar `Writer.add_file_simple` method
 https://github.com/halostatue/minitar/blob/a531136b17b9efdddf0a0f39537845b454c2371e/lib/minitar/writer.rb#L139

* Better default for mtime

If for some reason we cant get a time from a File object (very unlikely)
a better default is Time.now rather than 0.

* Update rakelib/artifacts.rake

Co-authored-by: João Duarte <[email protected]>

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Co-authored-by: João Duarte <[email protected]>
(cherry picked from commit d9b95bf)

# Conflicts:
#	rakelib/artifacts.rake

* Ensure any file object in a tar archive has an mtime (#18113)

* Ensure any file object in a tar archive has an mtime

Following up on #18091, when minitar
writes a directory or symlink it also needs explicit mtime. After inspecting
artifacts built from #18019 we see some other missing mtimes. This commit
ensures that information is explicitly passed to the minitar writer.

* Update rakelib/artifacts.rake

Co-authored-by: João Duarte <[email protected]>

---------

Co-authored-by: João Duarte <[email protected]>

* fix merge conflicts

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Co-authored-by: Cas Donoghue <[email protected]>
Co-authored-by: João Duarte <[email protected]>

Author: 3 people

rakelib/artifacts.rake

@@ -561,12 +561,14 @@ namespace "artifact" do
 
   def write_to_tar(tar, path, path_in_tar)
     stat = File.lstat(path)
+    # in the off-chance that mtime returns nil we don't want nil to be interpreted as epoch, so fall back to Time.now
+    mtime = (stat.mtime || Time.now).to_i
     if stat.directory?
-      tar.mkdir(path_in_tar, :mode => stat.mode)
+      tar.mkdir(path_in_tar, :mode => stat.mode, :mtime => mtime)
     elsif stat.symlink?
-      tar.symlink(path_in_tar, File.readlink(path), :mode => stat.mode)
+      tar.symlink(path_in_tar, File.readlink(path), :mode => stat.mode, :mtime => mtime)
     else
-      tar.add_file_simple(path_in_tar, :mode => stat.mode, :size => stat.size) do |io|
+      tar.add_file_simple(path_in_tar, :mode => stat.mode, :size => stat.size, :mtime => mtime) do |io|
         File.open(path, 'rb') do |fd|
           chunk = nil
           size = 0