merged branch char101/fix-ext-retval (PR #921)
merged branch char101/fix-ext-retval (PR #921)

This PR was merged into the twig-c-bug branch.

Commits
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e8d12da Fix empty string comparison
4311df3 added some missing test for Template::getAttribute()

Discussion
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Fix empty string comparison

Issue #920

Tobion/Twig,nicolas-grekas/Twig,nicolas-grekas/Twig,hhamon/Twig,bocharsky-bw/Twig,peterkokot/Twig,dkarvounaris/Twig,znerol/Twig,nicolas-grekas/Twig,bocharsky-bw/Twig,gamernetwork/Twig,framewr/Twig,robregonm/Twig,moltin/Twig,craue/Twig,Tobion/Twig,twigphp/Twig,framewr/Twig,iKwinto/Twig,hason/Twig,znerol/Twig,craue/Twig,hason/Twig,gencer/Twig,hhamon/Twig,jamessingizi/Twig,Tobion/Twig,nicolas-grekas/Twig,iKwinto/Twig,apishka/templater,bocharsky-bw/Twig,moltin/Twig,jamessingizi/Twig,Rvanlaak/Twig,markstory/Twig,gamernetwork/Twig,Rvanlaak/Twig,gencer/Twig,apishka/templater,iKwinto/Twig,robregonm/Twig,znerol/Twig,loi-chuanoi/Twig,derickr/Twig,phansys/Twig,fsw/Twig,phansys/Twig,hhamon/Twig,dkarvounaris/Twig,gamernetwork/Twig,huang53798584/Twig,fsw/Twig,markstory/Twig,huang53798584/Twig,jamessingizi/Twig,twigphp/Twig,Rvanlaak/Twig,derickr/Twig,nicolas-grekas/Twig,moufmouf/Twig,dkarvounaris/Twig,twigphp/Twig,framewr/Twig,fsw/Twig,moufmouf/Twig,moltin/Twig,hason/Twig,peterkokot/Twig,moufmouf/Twig,huang53798584/Twig,derickr/Twig,robregonm/Twig