Resolves: tdf#112215 null deref on missing optional ppd value

Change-Id: Iba45437332df963e1aa213c587071ab293f36390
Reviewed-on: https://gerrit.libreoffice.org/64164
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/generic/printer/ppdparser.cxx

@@ -848,13 +848,22 @@ PPDParser::PPDParser( const OUString& rFile ) :
     }
 
     // fill in direct values
-    if( (pKey = getKey( OUString( "ColorDevice" ) )) )
-        m_bColorDevice = pKey->getValue( 0 )->m_aValue.startsWithIgnoreAsciiCase( "true" );
+    if ((pKey = getKey(OUString("ColorDevice"))))
+    {
+        if (const PPDValue* pValue = pKey->getValue(0))
+            m_bColorDevice = pValue->m_aValue.startsWithIgnoreAsciiCase("true");
+    }
 
-    if( (pKey = getKey( OUString( "LanguageLevel" ) )) )
-        m_nLanguageLevel = pKey->getValue( 0 )->m_aValue.toInt32();
-    if( (pKey = getKey( OUString( "TTRasterizer" ) )) )
-        m_bType42Capable = pKey->getValue( 0 )->m_aValue.equalsIgnoreAsciiCase( "Type42" );
+    if ((pKey = getKey(OUString("LanguageLevel"))))
+    {
+        if (const PPDValue* pValue = pKey->getValue(0))
+            m_nLanguageLevel = pValue->m_aValue.toInt32();
+    }
+    if ((pKey = getKey(OUString("TTRasterizer"))))
+    {
+        if (const PPDValue* pValue = pKey->getValue(0))
+            m_bType42Capable = pValue->m_aValue.equalsIgnoreAsciiCase( "Type42" );
+    }
 }
 
 PPDParser::~PPDParser()