Add Font::uchr float-handling test

Add testUchrWithOutOfRangeFloat covering both the warning fix from the
previous commit (e161d7c) for out-of-range floats, INF and NAN, as well
as a check that floats in general are still cast to int (added in #623).

Note that the previous commit wrongly assumed that the cast warning was
introduced in PHP 8.1, but it was in fact introduced in PHP 8.5 only.

Previous PHP versions silently cast an unrepresentable float to system
dependent "weird" results (negative integers, 0-bytes).
See https://wiki.php.net/rfc/warnings-php-8-5 for details.

This change enables PHPUnit's failOnWarning option which will turn
warnings into actual test failures - the test in this commit as well as
the existing ParserTest::testIssue621 and ParserTest::testParseFile will
fail now without the patch in e161d7c.

Unrelated, minor convenience fix: this also increases the memory limit
for unit tests to 1GB (from default 128MB) to avoid out of memory issues
during the test run via phpunit.xml

Author: splitbrain

phpunit.xml

@@ -1,21 +1,33 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!-- https://phpunit.de/manual/current/en/appendixes.configuration.html -->
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd" backupGlobals="false" bootstrap="vendor/autoload.php" colors="true" processIsolation="false" stopOnFailure="false" cacheDirectory=".phpunit.cache" backupStaticProperties="false" displayDetailsOnTestsThatTriggerWarnings="true">
-  <php>
-    <ini name="error_reporting" value="-1"/>
-    <ini name="zend.enable_gc" value="0"/>
-    <ini name="error_reporting" value="-1"/>
-    <ini name="intl.error_level" value="0"/>
-    <ini name="display_errors" value="On"/>
-  </php>
-  <testsuites>
-    <testsuite name="all">
-      <directory>tests/PHPUnit</directory>
-    </testsuite>
-  </testsuites>
-  <source>
-    <include>
-      <directory>src</directory>
-    </include>
-  </source>
+<phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+    backupGlobals="false"
+    bootstrap="vendor/autoload.php"
+    colors="true"
+    processIsolation="false"
+    stopOnFailure="false"
+    cacheDirectory=".phpunit.cache"
+    backupStaticProperties="false"
+    displayDetailsOnTestsThatTriggerWarnings="true"
+    failOnWarning="true">
+    <php>
+        <ini name="error_reporting" value="-1"/>
+        <ini name="zend.enable_gc" value="0"/>
+        <ini name="error_reporting" value="-1"/>
+        <ini name="intl.error_level" value="0"/>
+        <ini name="display_errors" value="On"/>
+        <ini name="memory_limit" value="1G"/>
+    </php>
+    <testsuites>
+        <testsuite name="all">
+            <directory>tests/PHPUnit</directory>
+        </testsuite>
+    </testsuites>
+    <source>
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
 </phpunit>

tests/PHPUnit/Unit/FontTest.php

@@ -68,4 +68,36 @@ public function testDecodeTextIssue597(): void
         // compare result with expected value
         self::assertEquals('3cc2ab083e', bin2hex($result));
     }
+
+    /**
+     * A CMap could contain oversized hex values. hexdec() then returns a float
+     * larger than PHP_INT_MAX which cannot be cast to int. On PHP 8.5 this
+     * cast raises a "not representable as int" warning.
+     *
+     * Since these values can not represent valid Unicode code points anyway,
+     * it's safe to return Font::MISSING for them. This test checks that this
+     * is the case.
+     *
+     * The test relies on PhpUnit's failOnWarning="true" in phpunit.xml:
+     * a warning would error.
+     *
+     * @see https://github.com/smalot/pdfparser/pull/623
+     * @see https://github.com/smalot/pdfparser/pull/825
+     */
+    public function testUchrWithOutOfRangeFloat(): void
+    {
+        // a regular code point is still decoded
+        $this->assertEquals('A', Font::uchr(0x41));
+
+        // a float that fits into an integer is still cast and decoded; this is
+        // the reason uchr() accepts floats in the first place
+        $this->assertEquals('A', Font::uchr(65.0));
+
+        // floats that do not fit into an integer can never be a valid code
+        // point; the value below is produced by hexdec() of an oversized hex
+        // string taken from samples/bugs/Issue621.pdf
+        $this->assertEquals(Font::MISSING, Font::uchr(1.50646556872121E+28));
+        $this->assertEquals(Font::MISSING, Font::uchr(\INF));
+        $this->assertEquals(Font::MISSING, Font::uchr(\NAN));
+    }
 }