Bugfix — Issue #777: api/testcases create under project root → E_WARNING testproject.class.php:1045 + DB 1064 (empty external id)

Issue: #777 Branch: fix/issue-777 · Commits: aee98f47b (fix), 6eb98377a (regression suite) Status: FIXED & VERIFIED (2026-08-30)

Symptom

Creating a test case directly under the test project root via the modern BFF (POST /api/testcases/?action=create with parent_id = the test project root id) returned HTTP 200 but with an HTML error body instead of JSON:

DB Access Error - debug_print_backtrace()
#0 .../lib/functions/testcase.class.php(783): database->exec_query()
#1 .../lib/functions/testcase.class.php(432): testcase->createVersion()
#2 .../api/testcases/index.php(902): testcase->create(1, ...)

The events table (Event Viewer) received several E_WARNINGs (testcase.class.php:687, testproject.class.php:1045) and an ERROR ON exec_query() 1064 "SQL syntax ... empty tc_external_id". Orphaned nodes_hierarchy rows were left behind and no tcversions row was written.

Creating a test case under a testsuite parent worked fine (positive control).

Root cause chain

1. api/testcases/index.php:894 create action accepts parent_id = the test project root id — $checkWrite($parentId) (line 809 owningProjectOf) resolves that node to the project and only demands the mgt_modify_tc right, so the request is not rejected.
2. testcase::create() → create_tcase_only() (lib/functions/testcase.class.php:395).
3. lib/functions/testcase.class.php:687:

   $path2root = $this->tree_manager->get_path($parent_id);
   $tproject_id = $path2root[0]['parent_id'];
   

   tree::get_path() (lib/functions/tree.class.php:408/462) returns the node chain reversed and excluding the root node (recursion stops when parent_id is 0/NULL). For parent_id = the project root, get_path() returns [].
4. $tproject_id = null (E_WARNING "Undefined array key 0" / "Trying to access array offset on null" at testcase.class.php:687).
5. testproject::generateTestCaseNumber(null) (testproject.class.php:1012 → intval(null)=0) runs UPDATE ... SET tc_counter=tc_counter+1 WHERE id = 0 (0 rows) then SELECT tc_counter ... WHERE id=0 (0 rows) → $rs[0]['tc_counter'] at testproject.class.php:1045 → E_WARNING, returns null.
6. createVersion() (testcase.class.php:432/783) receives an empty tc_external_id → INSERT INTO tcversions (...,tc_external_id,...) VALUES(...,, ...) → SQL 1064.

Why it breaks (regression source): the _get_path intval() guard that stops recursion at root nodes makes the root itself invisible in the returned path. Every other get_path() consumer resolves from a child, where [0] is the node just below the root and [0]['parent_id'] is the project id — so they always see a non-empty path. Only the "parent IS the root" case yields an empty path.

Blast radius: get_path($parent_id) inside create_tcase_only() is the ONLY broken consumer for root parents. create_tcase_only() has 2 call sites: testcase::create() (testcase.class.php:395) and the copy/move path (testcase.class.php:2223). Both benefit; neither passes a non-testproject root in normal operation.

Approach — resolve owning project when parent IS the test project root (minimal fix)

lib/functions/testcase.class.php create_tcase_only() (lines ~685-697): when tree::get_path($parent_id) returns an empty/null path (parent is the tree root, i.e. a test case created directly under the test project root), fall back to $tproject_id = $parent_id; otherwise keep the original $path2root[0]['parent_id'] resolution (byte-for-byte unchanged for the testsuite/nested paths).

$path2root = $this->tree_manager->get_path($parent_id);
if( is_null($path2root) || count($path2root) == 0 )
{
  $tproject_id = $parent_id;
}
else
{
  $tproject_id = $path2root[0]['parent_id'];
}

Alternatives rejected:

• Reject the API request when parent_id is the root: changes behaviour (top-level test cases are legal in legacy TestLink) and does not fix the shared create_tcase_only() copy/move path.
• Change generateTestCaseNumber() to handle null: addresses the symptom at the wrong layer and would affect other callers.

Files changed

File	Change
lib/functions/testcase.class.php	+12/-2 in create_tcase_only(): fall back to $parent_id when get_path() returns empty
tmp/TLU_Test_Cases.md	+Suite 777 (4 test cases, 4/4 PASS, re-executed on fresh DB)

Verification

• php -l lib/functions/testcase.class.php → no syntax errors.
• Primary (fresh DB, admin browser session): created project Repro Project id=1, then POST /api/testcases/?action=create {"parent_id":1,...} → HTTP 200 {"status":"ok","id":5,"message":"Test case created"}; tcversions row written with non-empty tc_external_id=2 (pre-fix: DB 1064 page, no tcversions row).
• Regression matrix:
  1. TC directly under project root → succeeds, correct external id ✅
  2. TC under a testsuite (suite_create id=8 then create id=9) → HTTP 200, tcversion tc_external_id=3 ✅
  3. Nested Suite→Suite→TC (Sub Suite id=12, Nested TC id=13) → HTTP 200, tcversion tc_external_id=4 ✅
  4. Event Viewer / events: only 2 AUDIT (login + tproject created) rows, 0 ERROR / 0 WARNING after all creates ✅