Smarty is not compatible with PHP 8.0

[ildar-aim]

https://github.com/php/php-src/blob/php-8.0.0beta1/UPGRADING

For example, this patch causes a fatal error

diff --git a/demo/templates/index.tpl b/demo/templates/index.tpl
index 1fbb6d3..291c3fa 100644
--- a/demo/templates/index.tpl
+++ b/demo/templates/index.tpl
@@ -1,6 +1,10 @@
 {config_load file="test.conf" section="setup"}
 {include file="header.tpl" title=foo}
 
+
+{if $smarty.const.TEST}
+{$smarty.const.TEST}
+{/if}
 <PRE>
 
 {* bold and title are read from the config file *}

Fatal error: Uncaught Error: Undefined constant "TEST" in public_html/smarty/demo/templates_c/234d0264d74c0efb651cf2c28d8975810c02182d_0.file.index.tpl.cache.php:35

Stack trace:
#0 public_html/smarty/demo/templates_c/234d0264d74c0efb651cf2c28d8975810c02182d_0.file.index.tpl.cache.php(35): constant('TEST')
#1 public_html/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_5f32594c42fb41_62206325(Object(Smarty_Internal_Template))
#2 public_html/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#3 public_html/smarty/libs/sysplugins/smarty_internal_runtime_updatecache.php(38): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#4 public_html/smarty/libs/sysplugins/smarty_template_cached.php(143): Smarty_Internal_Runtime_UpdateCache->updateCache(Object(Smarty_Template_Cached), Object(Smarty_Internal_Template), f#5 public_html/smarty/libs/sysplugins/smarty_internal_template.php(211): Smarty_Template_Cached->render(Object(Smarty_Internal_Template), false)
#6 public_html/smarty/libs/sysplugins/smarty_internal_templatebase.php(232): Smarty_Internal_Template->render(false, 1)
#7 public_html/smarty/libs/sysplugins/smarty_internal_templatebase.php(134): Smarty_Internal_TemplateBase->_execute(Object(Smarty_Internal_Template), NULL, NULL, NULL, 1)
#8 public_html/smarty/demo/index.php(36): Smarty_Internal_TemplateBase->display('index.tpl')
#9 {main}

due to
https://github.com/php/php-src/blob/php-8.0.0beta1/UPGRADING

The code like this should not be used

<?php if (@constant('TEST')) {
echo @constant('TEST');?>

<?php }?>

[AnrDaemon]

Can you please provide a patch as well? Use defined('CONSTANT') to detect the presence of it.

[wisskid]

Planned availability of PHP8 is Nov 26 2020. We have some work to do here.

[AnrDaemon]

Can we start by setting up Travis to run PHP8 tests?

Also, https://travis-ci.org/github/smarty-php/smarty/jobs/713094965 while we're at it.

[wisskid]

I've set-up a vagrant box with debian 10 and compiled php8beta3 with mbstring. After removing the $errcontext variable everywhere (see #604, but completely removed it, and removed from unit tests as well) the remaining fails from the unit tests seem to be limited:

......................................................EEEF...   61 / 2393 (  2%)
.............................................................  122 / 2393 (  5%)
.....SSSSSS..................................................  183 / 2393 (  7%)
.............SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS  244 / 2393 ( 10%)
SSSSSSSSSSSS.................................................  305 / 2393 ( 12%)
..............F..............................................  366 / 2393 ( 15%)
......................................................R...R..  427 / 2393 ( 17%)
........................................................R...R  488 / 2393 ( 20%)
.............................................................  549 / 2393 ( 22%)
................S.S.S.........E..........................E..E  610 / 2393 ( 25%)
EE.EE.EE.....................................................  671 / 2393 ( 28%)
.............................................................  732 / 2393 ( 30%)
.............................................................  793 / 2393 ( 33%)
.............................................................  854 / 2393 ( 35%)
.............................................................  915 / 2393 ( 38%)
.............................................................  976 / 2393 ( 40%)
............................................................. 1037 / 2393 ( 43%)
............................................................. 1098 / 2393 ( 45%)
............................................................. 1159 / 2393 ( 48%)
............................................................. 1220 / 2393 ( 50%)
............................................................. 1281 / 2393 ( 53%)
...................................E........................E 1342 / 2393 ( 56%)
............................................................. 1403 / 2393 ( 58%)
............................................................. 1464 / 2393 ( 61%)
............................................................. 1525 / 2393 ( 63%)
............................................................. 1586 / 2393 ( 66%)
............................................................. 1647 / 2393 ( 68%)
..........................................................E.. 1708 / 2393 ( 71%)
...................R......................................... 1769 / 2393 ( 73%)
............................................................. 1830 / 2393 ( 76%)
............................................................. 1891 / 2393 ( 79%)
............................................................. 1952 / 2393 ( 81%)
............................................................. 2013 / 2393 ( 84%)
............................................................. 2074 / 2393 ( 86%)
............................................................. 2135 / 2393 ( 89%)
............................................................. 2196 / 2393 ( 91%)
.........E................................................... 2257 / 2393 ( 94%)
............................................................. 2318 / 2393 ( 96%)
......................................................R...... 2379 / 2393 ( 99%)
..............                                                2393 / 2393 (100%)

Time: 2.68 minutes, Memory: 32.00MB

There were 16 errors:

1) UndefinedTemplateVarTest::testE_NoticeDisabled
Undefined array key "foo"

/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/d6b0fd5b3e3e321065cf5ac52a6e7fb7c73228da_0.file.001_include.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:385
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/fa1c875f6451a656c3a14b230296e25b244759f7_0.file.001_main.tpl.php:25
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/UndefinedTemplateVarTest.php:33

2) UndefinedTemplateVarTest::testE_NoticeDisabledTplObject_1
Undefined array key "foo"

/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/d6b0fd5b3e3e321065cf5ac52a6e7fb7c73228da_0.file.001_include.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:385
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/fa1c875f6451a656c3a14b230296e25b244759f7_0.file.001_main.tpl.php:25
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/UndefinedTemplateVarTest.php:46

3) UndefinedTemplateVarTest::testE_NoticeDisabledTplObject_2
Undefined array key "foo"

/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/d6b0fd5b3e3e321065cf5ac52a6e7fb7c73228da_0.file.001_include.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:385
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/fa1c875f6451a656c3a14b230296e25b244759f7_0.file.001_main.tpl.php:25
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/UndefinedTemplateVarTest.php:56

4) SecurityTest::testTrustedUri
SmartyException: {fetch} cannot read resource 'https://www.smarty.net/docs/en/preface.tpl'

/smarty/smarty/libs/plugins/function.fetch.php:196
/smarty/smarty/tests/UnitTests/SecurityTests/templates_c/d9ab7eaa83efe8c19a07555b9cfd08c53ea34a13_0.string.php:19
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SecurityTests/SecurityTest.php:371

5) ClearAllAssignBCTest::testSmarty2ClearAllAssignInSmarty
Undefined array key "foo"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAllAssign/ClearAllAssignBCTest.php:38

6) ClearAllAssignTest::testClearAllAssignInTemplate
Undefined array key "blar"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAllAssign/ClearAllAssignTest.php:51

7) ClearAllAssignTest::testClearAllAssignInData
Undefined array key "bar"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAllAssign/ClearAllAssignTest.php:61

8) ClearAllAssignTest::testClearAllAssignInSmarty
Undefined array key "foo"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAllAssign/ClearAllAssignTest.php:71

9) ClearAssignBCTest::testSmarty2ClearAssign
Undefined array key "blar"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAssign/ClearAssignBCTest.php:38

10) ClearAssignBCTest::testSmarty2ArrayClearAssign
Undefined array key "foo"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAssign/ClearAssignBCTest.php:45

11) ClearAssignTest::testClearAssign
Undefined array key "blar"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAssign/ClearAssignTest.php:41

12) ClearAssignTest::testArrayClearAssign
Undefined array key "foo"

/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/SmartyMethodsTests/ClearAssign/ClearAssignTest.php:51

13) CompileForeachTest::testForeach with data set #6 ('{foreach item=x from=$foo}{$x...reach}', null, 'else', '', 6)
Undefined array key "foo"

/smarty/smarty/tests/UnitTests/TemplateSource/TagTests/Foreach/templates_c/1e8203e7f797131c6f9b778d81729d48af47a71c_0.file.testForeach_6.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/TemplateSource/TagTests/Foreach/CompileForeachTest.php:50

14) CompileForeachTest::testForeach with data set #31 ('{foreach $foo as $x}{$x}{fore...reach}', null, 'else', '', 31)
Undefined array key "foo"

/smarty/smarty/tests/UnitTests/TemplateSource/TagTests/Foreach/templates_c/86c740f8ab8059c9a233fd62d9de76dac89315e4_0.file.testForeach_31.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/TemplateSource/TagTests/Foreach/CompileForeachTest.php:50

15) PluginFunctionFetchTest::testFetchUri
SmartyException: {fetch} cannot read resource 'https://www.smarty.net/docs/en/preface.tpl'

/smarty/smarty/libs/plugins/function.fetch.php:196
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/TemplateSource/TagTests/PluginFunction/PluginFunctionFetchTest.php:37

16) ConstantsTest::testConstantsUndefined
Error: Undefined constant "MYCONSTANT2"

/smarty/smarty/tests/UnitTests/TemplateSource/ValueTests/ConstantTests/templates_c/0256f03ee3c7feef478edf934160e395238b0231_0.string.php:18
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/TemplateSource/ValueTests/ConstantTests/ConstantsTest.php:82

--

There were 2 failures:

1) UndefinedTemplateVarTest::testE_Notice
Failed asserting that exception of type "PHPUnit\Framework\Error\Warning" matches expected exception "PHPUnit_Framework_Error_Notice". Message was: "Undefined array key "foo"" at
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/d6b0fd5b3e3e321065cf5ac52a6e7fb7c73228da_0.file.001_include.tpl.php:24
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:385
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/templates_c/fa1c875f6451a656c3a14b230296e25b244759f7_0.file.001_main.tpl.php:25
/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php:123
/smarty/smarty/libs/sysplugins/smarty_template_compiled.php:114
/smarty/smarty/libs/sysplugins/smarty_internal_template.php:216
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:232
/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php:116
/smarty/smarty/tests/UnitTests/A_2/UndefinedTemplateVar/UndefinedTemplateVarTest.php:70
/smarty/smarty/vendor/phpunit/phpunit/phpunit:53
.

2) ConfigVarTest::testConfigUndefinedNotice
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'Undefined variable: foo'
+'Undefined variable $foo'

/smarty/smarty/tests/UnitTests/ConfigFileTests/file/ConfigVarTest.php:406

--

There were 6 risky tests:

1) FileResourceTest::testGetCompiledTimestampPrepare
This test did not perform any assertions

2) FileResourceTest::testMustCompileTouchedSourcePrepare
This test did not perform any assertions

3) PhpResourceTest::testIsCachedTouchedSourcePrepare
This test did not perform any assertions

4) PhpResourceTest::testSmartyIsCachedPrepare
This test did not perform any assertions

5) PluginFunctionHtmlImageTest::testFoo
This test did not perform any assertions

6) ScopeTest::testFunctionScope
This test did not perform any assertions

ERRORS!
Tests: 2393, Assertions: 3310, Errors: 16, Failures: 2, Skipped: 69, Risky: 6.

Mostly changes to the unit tests themselves.

[wisskid]

Yes, many of the "undefined array key ..." errors are easily fixed: "A number of notices have been converted into warnings". We should just up the setErrorReporting to ~E_WARNING.

[AnrDaemon]

Can we set the Travis first, so pull requests could start flowing?

[wisskid]

Yes, but to re-enable it (I disabled php nightly recently) we'll have to fix the unit tests first, as they all fail now. I'll take a shot at it.

[wisskid]

See #608

[caugner]

Yes, many of the "undefined array key ..." errors are easily fixed: "A number of notices have been converted into warnings". We should just up the setErrorReporting to ~E_WARNING.

@wisskid I wonder if the Smarty_Internal_Data->tpl_vars array couldn't instead be converted to a wrapper object (wrapping the array and implementing ArrayAccess) that returns null for non-existing items? This would avoid the E_WARNING for all cases where users rely on non-assigned vars to be null-ish, so we could still report other warnings.

For nested cases, an equivalent of the null-coalescing operator (?? / 7.0+) and/or the nullsafe operator (?-> / 8.0+) would be helpful to be usable inside Smarty templates, e.g.:

{if $object?.attribute?.nested}
{/if}

(which would not cause any warning if any of the hierarchy is not set/null)

[Bigbear7]

Just switched over our test site running on Smarty 3.1.36 to PHP 8. The content is shown, no white screen. So application doesn't bail out. However the logs are filled with: Undefined array key "XXX". The vote for lifting that from notice to warning in PHP RFC Reclassifying engine warnings was 42 to 21... Any hope on fixing this besides changing errorreporting?

[AnrDaemon]

Find where Smarty trap internal errors and see if you can amend for that. Though that would be a workaround at most.

[Bigbear7]

Well, a slightly quick & dirty fix is the following line of code when initialising smarty:
$smarty = new Smarty();
$smarty->setErrorReporting(E_ALL & ~E_WARNING & ~E_NOTICE);

I have close to zero warnings today when running site on PHP 7.4 with Smarty, so besides muting out other relevant PHP 8 warnings, it feels a bit safe to do so. I also assume this function only affects error levels within Smarty, but I'll check.