RepeatedHtmlEntityEncoding

warning native off by default

Group: Probable bugs

Detect htmlspecialchars or htmlentities directly nesting an equivalent encoding call with matching flags/encoding and default or true double_encode.

Example

<?php
echo htmlspecialchars(htmlspecialchars($text));

Reported:

• line 2: Encode HTML entities at one intended output boundary.

Detection

• Report htmlspecialchars or htmlentities directly nesting an equivalent encoding call with matching flags/encoding and default or true double_encode.
• Resolve builtin calls and named arguments before checking the contract. Project-local callees are considered only when their bodies or immutable summaries establish the required facts. The default is disabled; enable only when the stated intent matches the application.
• For flow-dependent conditions, require a reachable source-to-use path with no intervening invalidation. Unknown calls, ambiguous aliases, recursion or analysis-budget exhaustion cannot establish definite facts.

Exceptions (no report)

• Different contexts/options, double_encode false on the outer call and intentionally literal entity rendering are excluded.
• When either call receives an unpacked argument (...$options), its flags and encoding are unknown and may differ: no report.
• Unresolved targets, incomplete required facts, suppressed findings and PHP versions lacking the referenced API or language feature produce no report. User declarations shadowing builtin names are not builtin contracts.

Fix

No automatic fix: repeated encoding can intentionally display entity syntax.

PHP versions

Apply only on PHP versions supporting the referenced APIs and syntax (within PHP 5.3–8.5). Builtin behavior and argument contracts follow the configured PHP version. Extension-specific calls require resolved extension API symbols; do not treat same-named application functions as extension calls.

Options

None. Enable or disable this rule through normal rule configuration.

Configure

In custos.json:

{
  "rules": {
    "RepeatedHtmlEntityEncoding": {
      "enabled": true
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file):

// @custos-ignore RepeatedHtmlEntityEncoding