Bugfix — Issue #979: tcView E_WARNING foreach() on null keyword set (testcase.class.php:9347)

Problem

Rendering a test case that has no keywords — neither own nor inherited from an ancestor testsuite — fired PHP warnings that landed in the Event Viewer / events table:

E_WARNING foreach() argument must be of type array|object, null given
  - in lib/functions/testcase.class.php - Line 9347

Plus, for every keywordless test case, a set of str_replace() parameter deprecations at testcase.class.php:9358 (Passing null to parameter #1/#2).

The symptoms only appear on PHP 8.x (E_WARNING / E_DEPRECATED). Keywordless TCs are the common case on a fresh database.

Root Cause

renderSpecialTSuiteKeywords() (lib/functions/testcase.class.php:9313) builds a static cache:

$skwSet[$tcase_id] = $this->getPathLayered($tcase_id,$optSKW);

getPathLayered() (testcase.class.php:5578) initialises $xtree = null and only fills it for nodes whose node_table == 'testsuites' (line 5602). Two failure modes:

1. Test case attached directly under the project root — get_path() returns [testproject, testcase] with no testsuite node, so $xtree stays null and getPathLayered() returns null. $skwSet becomes the array [tcase_id => null], which is not null, so the guard if( is_null($skwSet) ) return; (old line 9330) never triggers. The double foreach at line 9346-9347 then iterates the null element → E_WARNING foreach() ... null given at 9347. This is the primary reported symptom.
2. No @# special keyword anywhere in the chain — the cache holds testsuite entries whose data_management is null, so nothing ever gets appended to $searchSet/$replaceSet, which stay null → str_replace(null,null,...) raises deprecations at 9358 for all keywordless TCs (including suite children).

Fix

File: lib/functions/testcase.class.php — 3 changes in renderSpecialTSuiteKeywords():

1. Default a null getPathLayered() result to an empty array when filling the cache (fixes the foreach() E_WARNING):

   $skwSet[$tcase_id] = $this->getPathLayered($tcase_id,$optSKW);
   if( is_null($skwSet[$tcase_id]) ) {
     $skwSet[$tcase_id] = array();
   }
   

2. Harden the early-return guard from is_null($skwSet) to empty($skwSet) (the array is never null once an element is stored).

3. Initialise the search/replace sets to array() instead of null (fixes the str_replace() deprecations for keywordless TCs):

   $searchSet = array();
   $replaceSet = array();
   

Behaviour is unchanged when special keywords DO exist — str_replace() on an empty array of replacements simply leaves summary/preconditions untouched. No i18n impact, no user-facing strings changed.

Files Changed

File	Change
lib/functions/testcase.class.php	renderSpecialTSuiteKeywords() — null→array() cache default, empty() guard, array() search/replace init (7+ / 4-)
docs/screenshots/issue-979-tcview-no-warning-postfix.png	post-fix TC view render (new)
docs/screenshots/issue-979-event-viewer-postfix.png	Event Viewer after post-fix renders (new)

Commit bed7f8561 on branch fix/issue-979.

Testing / Evidence

• Primary symptom (before): harness calling renderSpecialTSuiteKeywords() for a root-attached keywordless TC captured testcase.class.php:9347 foreach() argument must be of type array|object, null given plus 4 str_replace() deprecations; the browser produced the same line-9347 event (event id 24, 10:02:00).
• Primary symptom (after): same harness → 0 warnings from testcase.class.php; browser re-render of archiveData.php?edit=testcase&id=50 → clean TC view, no new 9347/9358 event in the Event Viewer.
• Keywordless suite child (TC30): 4 str_replace() deprecations → 0.
• Positive control: keyword @#DYN on the ancestor suite → summary my @#DYN summary renders as my DYN:Suite summary, still 0 warnings → replacement logic intact.
• Syntax gate: php -l → No syntax errors detected.
• Blast radius: renderSpecialTSuiteKeywords is referenced only inside testcase.class.php (3 occurrences: 1 def + 2 calls at lines 2944 / 4324); neither signature nor output contract changed.
• Code review subagent: PASS (see review notes).
• Event Viewer: no new Error/Warning from this fix. Unrelated pre-existing template warnings (label keys, testcase.class.php:7490) remain tracked separately.

Screenshots

Regression Test Case

Suite Regression — Issue #979 (7/7 PASS) appended to tmp/TLU_Test_Cases.md: root-attached keywordless TC harness, suite-child keywordless harness, positive @# keyword control, browser render of the affected view, Event Viewer accounting, php -l gate, and diff-scope check.