Fixed an issue that could cause compression to abort on growing files.

Reported by Jesper St John, Aleksandr Rogozin.

doc/xml/release.xml

@@ -13,6 +13,15 @@
         <release date="XXXX-XX-XX" version="1.23dev" title="UNDER DEVELOPMENT">
             <release-core-list>
                 <release-bug-list>
+                    <release-item>
+                        <release-item-contributor-list>
+                            <release-item-ideator id="stjohn.jesper"/>
+                            <release-item-ideator id="rogozin.aleksandr"/>
+                        </release-item-contributor-list>
+
+                        <p>Fixed an issue that could cause compression to abort on growing files.</p>
+                    </release-item>
+
                     <release-item>
                         <release-item-contributor-list>
                             <release-item-ideator id="cox.william"/>
@@ -3286,6 +3295,11 @@
             <contributor-id type="github">eradman</contributor-id>
         </contributor>
 
+        <contributor id="rogozin.aleksandr">
+            <contributor-name-display>Aleksandr Rogozin</contributor-name-display>
+            <contributor-id type="github">arogozin</contributor-id>
+        </contributor>
+
         <contributor id="shang.cynthia">
             <contributor-name-display>Cynthia Shang</contributor-name-display>
             <contributor-id type="github">cmwshang</contributor-id>
@@ -3301,6 +3315,11 @@
             <contributor-id type="github">gregscds</contributor-id>
         </contributor>
 
+        <contributor id="stjohn.jesper">
+            <contributor-name-display>Jesper St John</contributor-name-display>
+            <contributor-id type="github">Underhunden</contributor-id>
+        </contributor>
+
         <contributor id="vernick.todd">
             <contributor-name-display>Todd Vernick</contributor-name-display>
             <contributor-id type="github">gintoddic</contributor-id>

lib/pgBackRest/Common/Io/Handle.pm

@@ -55,6 +55,9 @@ sub new
     # Size tracks number of bytes read and written
     $self->{lSize} = 0;
 
+    # Initialize EOF to false
+    $self->{bEOF} = false;
+
     # Return from function and log return values if any
     return logDebugReturn
     (
@@ -63,6 +66,17 @@ sub new
     );
 }
 
+####################################################################################################################################
+# eof - have reads reached eof?
+#
+# Note that there may be more bytes to be read but this is set to true whenever there is a zero read and back to false on a
+# non-zero read.
+####################################################################################################################################
+sub eof
+{
+    return shift->{bEOF};
+}
+
 ####################################################################################################################################
 # read - read data from handle
 ####################################################################################################################################
@@ -93,6 +107,9 @@ sub read
     # Update size
     $self->{lSize} += $iActualSize;
 
+    # Update EOF
+    $self->{bEOF} = $iActualSize == 0 ? true : false;
+
     return $iActualSize;
 }
 

lib/pgBackRest/Storage/Filter/Gzip.pm

@@ -126,6 +126,8 @@ sub read
 
     if ($self->{strCompressType} eq STORAGE_COMPRESS)
     {
+        return 0 if $self->eof();
+
         my $lSizeBegin = defined($$rtBuffer) ? length($$rtBuffer) : 0;
         my $lUncompressedSize;
         my $lCompressedSize;
@@ -172,8 +174,8 @@ sub read
             }
         }
 
-        # Actual size is the lesser of the local buffer size or requested size - if the local buffer is smaller than the requested size
-        # it means that there was nothing more to be read.
+        # Actual size is the lesser of the local buffer size or requested size - if the local buffer is smaller than the requested
+        # size it means that there was nothing more to be read
         my $iActualSize = $self->{lUncompressedBufferSize} < $iSize ? $self->{lUncompressedBufferSize} : $iSize;
 
         # Append the to the request buffer

test/lib/pgBackRestTest/Module/Common/CommonIoHandleTest.pm

@@ -105,12 +105,15 @@ sub run
         $self->testResult(sub {$oIoHandle->read(\$tContent, $iFileLengthHalf)}, $iFileLengthHalf, '    read part 1');
         $self->testResult($tContent, substr($strFileContent, 0, $iFileLengthHalf), '    check read');
 
+        $self->testResult(sub {$oIoHandle->eof()}, false, '    not eof');
+
         $self->testResult(
             sub {$oIoHandle->read(
                 \$tContent, $iFileLength - $iFileLengthHalf)}, $iFileLength - $iFileLengthHalf, '    read part 2');
         $self->testResult($tContent, $strFileContent, '    check read');
 
-        $self->testResult(sub {$oIoHandle->read(\$tContent, 1)}, 0, '    eof');
+        $self->testResult(sub {$oIoHandle->read(\$tContent, 1)}, 0, '    zero read');
+        $self->testResult(sub {$oIoHandle->eof()}, true, '    eof');
     }
 
     ################################################################################################################################

test/lib/pgBackRestTest/Module/Storage/StorageFilterGzipTest.pm

@@ -182,6 +182,27 @@ sub run
         $self->testResult(
             sub {sha1_hex(${storageTest()->get($strFile)})}, '1c7e00fd09b9dd11fc2966590b3e3274645dd031', '    check content');
 
+        #---------------------------------------------------------------------------------------------------------------------------
+        $tBuffer = undef;
+
+        my $oFile = $self->testResult(
+            sub {storageTest()->openWrite($strFile)}, '[object]', 'open file to extend during compression');
+
+        $oGzipIo = $self->testResult(
+            sub {new pgBackRest::Storage::Filter::Gzip($oDriver->openRead($strFile), {lCompressBufferMax => 4194304})},
+            '[object]', '    new read compress');
+
+        $self->testResult(sub {$oFile->write(\$strFileContent)}, length($strFileContent), '   write first block');
+        $self->testResult(sub {$oGzipIo->read(\$tBuffer, 2000000) > 0}, true, '    read compressed first block (compression done)');
+
+        $self->testResult(sub {$oFile->write(\$strFileContent)}, length($strFileContent), '   write second block');
+        $self->testResult(sub {$oGzipIo->read(\$tBuffer, 2000000)}, 0, '    read compressed  = 0');
+
+        $self->testResult(sub {storageTest()->put($strFileGz, $tBuffer) > 0}, true, '    put content');
+        executeTest("gzip -df ${strFileGz}");
+        $self->testResult(
+            sub {${storageTest()->get($strFile)}}, $strFileContent, '    check content');
+
         #---------------------------------------------------------------------------------------------------------------------------
         storageTest()->put($strFileGz, $strFileContent);