substInFile: fix writing to zero-sized or nonexistent files (#460),

eof does not seem to return true anymore for filehandles vivified
through select  (behavior change seems introduced by upstream perl
commit 32e653230c7ccc7fa595b1ab68502c6eb66ff980)

2 files changed, 12 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index b026727..5763bfb 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+- substInFile: fix writing to zero-sized or nonexistent files (#460),
+  eof does not seem to return true anymore for filehandles vivified
+  through select  (behavior change seems introduced by upstream perl
+  commit 32e653230c7ccc7fa595b1ab68502c6eb66ff980)
+
 Version 1.2.27 - 2 February 2011, by Eugeni Dodonov
 
 - add cp_afx command
diff --git a/lib/MDK/Common/File.pm b/lib/MDK/Common/File.pm
index a44c479..4dbb99d 100644
--- a/lib/MDK/Common/File.pm
+++ b/lib/MDK/Common/File.pm
@@ -342,11 +342,15 @@ sub substInFile(&@) {
 	fsync($F);
 	unlink "$file$^I"; # remove old backup now that we have closed new file
     } else {
-	local *F; my $old = select F; # that way eof return true
+	#- special handling for zero-sized or nonexistent files
+	#- because while (<>) will not do any iteration
+	open(my $F, "+> $file") or return;
+	#- "eof" without an argument uses the last file read
+	my $dummy = <$F>;
 	local $_ = '';
 	&$f($_);
-	select $old;
-	eval { output($file, $_) };
+	print $F $_;
+	fsync($F);
     }
 }