Fix version_compare() shorter operand parity (#4796)

ext/standard/VmInfo.php

@@ -201,8 +201,8 @@ private static function canonicalizeVersion(string $version): string
                     $buf .= '.';
                 }
             } elseif (
-                (!ctype_digit($lp) && ctype_digit($ch))
-                || (ctype_digit($lp) && !ctype_digit($ch))
+                (self::isVersionNonDigitChar($lp) && self::isVersionDigitChar($ch))
+                || (self::isVersionDigitChar($lp) && self::isVersionNonDigitChar($ch))
             ) {
                 if ('.' !== $lq) {
                     $buf .= '.';
@@ -224,6 +224,18 @@ private static function canonicalizeVersion(string $version): string
         return $buf;
     }
 
+    /** php-src versioning.c isdig(): digit excluding '.' */
+    private static function isVersionDigitChar(string $ch): bool
+    {
+        return ctype_digit($ch);
+    }
+
+    /** php-src versioning.c isndig(): non-digit excluding '.' */
+    private static function isVersionNonDigitChar(string $ch): bool
+    {
+        return !ctype_digit($ch) && '.' !== $ch;
+    }
+
     private static function compareSpecialVersionForms(string $form1, string $form2): int
     {
         /** @var array<string, int> */

lib/AOT/runtime/phpc_info.c

@@ -192,8 +192,8 @@ static char *phpc_canonicalize_version(const char *version)
                 *q++ = '.';
             }
         } else if (
-            (!isdigit((unsigned char) lp) && isdigit((unsigned char) *p))
-            || (isdigit((unsigned char) lp) && !isdigit((unsigned char) *p))
+            (!isdigit((unsigned char) lp) && '.' != lp && isdigit((unsigned char) *p))
+            || (isdigit((unsigned char) lp) && !isdigit((unsigned char) *p) && '.' != *p)
         ) {
             if ('.' != lq) {
                 *q++ = '.';

test/compliance/VersionCompareVMTest.php

@@ -17,6 +17,10 @@ public static function providePHPTests(): \Generator
             __DIR__.'/cases/stdlib/version_compare.phpt',
             'version_compare.phpt'
         );
+        yield 'version_compare_partial.phpt' => self::parsePHPT(
+            __DIR__.'/cases/stdlib/version_compare_partial.phpt',
+            'version_compare_partial.phpt'
+        );
     }
 
     public function setUp(): void

test/compliance/cases/stdlib/version_compare_partial.phpt

@@ -0,0 +1,11 @@
+--TEST--
+stdlib version_compare shorter operand parity (#4796)
+--FILE--
+<?php
+echo version_compare('8.2.31', '8.2', '>=') ? "ge\n" : "no\n";
+echo version_compare('8.2', '8.2.31', '<=') ? "le\n" : "no\n";
+echo version_compare('8.2.31', '8.2.0', '>=') ? "ge0\n" : "no\n";
+--EXPECT--
+ge
+le
+ge0

test/tmp/repro-version-compare-partial.php

@@ -0,0 +1,4 @@
+<?php
+declare(strict_types=1);
+var_export(version_compare('8.2.31', '8.2', '>='));
+echo PHP_EOL;