From 6a01db2b3297fc103577b8bd25da011f09fc8a17 Mon Sep 17 00:00:00 2001
From: David Steele <david@crunchydata.com>
Date: Wed, 2 May 2018 12:06:12 -0400
Subject: [PATCH] Fix delta restore failing when a linked file was missing.

---
 doc/xml/release.xml           |  4 ++++
 lib/pgBackRest/RestoreFile.pm | 16 +++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/doc/xml/release.xml b/doc/xml/release.xml
index 868582d50..0e916d32e 100644
--- a/doc/xml/release.xml
+++ b/doc/xml/release.xml
@@ -32,6 +32,10 @@
                         <p>Fix <br-option>archive-copy</br-option> throwing <quote>path not found</quote> error for incr/diff backups.</p>
                     </release-item>
 
+                    <release-item>
+                        <p>Fix delta restore failing when a linked file was missing.</p>
+                    </release-item>
+
                     <release-item>
                         <release-item-contributor-list>
                             <release-item-ideator id="adams.clinton"/>
diff --git a/lib/pgBackRest/RestoreFile.pm b/lib/pgBackRest/RestoreFile.pm
index a6fa14df5..1c08a3c5d 100644
--- a/lib/pgBackRest/RestoreFile.pm
+++ b/lib/pgBackRest/RestoreFile.pm
@@ -9,6 +9,7 @@ use Carp qw(confess);
 
 use Exporter qw(import);
     our @EXPORT = qw();
+use Fcntl qw(:mode);
 use File::Basename qw(dirname);
 use File::stat qw(lstat);
 
@@ -77,6 +78,7 @@ sub restoreFile
     my $oStorageDb = storageDb();
     my $bCopy = true;
 
+    # Zero file if requested
     if ($bZero)
     {
         $bCopy = false;
@@ -90,16 +92,20 @@ sub restoreFile
 
         $oDestinationFileIo->close();
     }
-    elsif ($oStorageDb->exists($strDbFile))
+    # Perform delta if requested
+    elsif ($bDelta)
     {
-        # Perform delta if requested
-        if ($bDelta)
+        my $oStat = $oStorageDb->info($strDbFile, {bIgnoreMissing => true});
+
+        # Do the delta if the file exists and is not a link or the link destination exists
+        if (defined($oStat) &&
+            (!S_ISLNK($oStat->mode) ||
+                $oStorageDb->exists(
+                    $oStorageDb->pathAbsolute(dirname($strDbFile), $oStorageDb->{oDriver}->linkDestination($strDbFile)))))
         {
             # If force then use size/timestamp delta
             if ($bForce)
             {
-                my $oStat = lstat($strDbFile);
-
                 # Make sure that timestamp/size are equal and that timestamp is before the copy start time of the backup
                 if (defined($oStat) && $oStat->size == $lSize &&
                     $oStat->mtime == $lModificationTime && $oStat->mtime < $lCopyTimeStart)