fix: prevent preg_replace null from truncating files to 0 bytes

preg_replace returns null on error. Without a null check, the result
was written to files as empty content, destroying all XML manifests
during the release pipeline.

Added null guards to all file_put_contents calls after preg_replace
in version_set_platform.php, version_check.php, and version_bump.php.

Authored-by: Moko Consulting
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cli/version_bump.php

@@ -125,7 +125,9 @@ if (file_exists($mokoManifest) && !empty($mokoContent)) {
         $mokoContent,
         1
     );
-    file_put_contents($mokoManifest, $updated);
+    if ($updated !== null) {
+        file_put_contents($mokoManifest, $updated);
+    }
 }
 
 // -- Update README.md --
@@ -136,7 +138,9 @@ if (file_exists($readme) && !empty($readmeContent)) {
         $readmeContent,
         1
     );
-    file_put_contents($readme, $updated);
+    if ($updated !== null) {
+        file_put_contents($readme, $updated);
+    }
 }
 
 // -- Cascade to ALL Joomla extension XML manifests --
@@ -160,7 +164,7 @@ foreach ($xmlPatterns as $pattern) {
             "<version>{$newFull}</version>",
             $content
         );
-        if ($newContent !== $content) {
+        if ($newContent !== null && $newContent !== $content) {
             file_put_contents($xmlFile, $newContent);
             $updatedFiles[] = substr($xmlFile, strlen($root) + 1);
         }

cli/version_check.php

@@ -99,13 +99,15 @@ if (count($uniqueVersions) === 1) {
         // Fix README.md
         if (isset($versions['README.md']) && $versions['README.md'] !== $highestVersion) {
             $content = file_get_contents($readme);
-            $content = preg_replace(
+            $updated = preg_replace(
                 '/(VERSION:\s*)\d{2}\.\d{2}\.\d{2}/m',
                 '${1}' . $highestVersion,
                 $content,
                 1
             );
-            file_put_contents($readme, $content);
+            if ($updated !== null) {
+                file_put_contents($readme, $updated);
+            }
             echo "  Fixed: README.md -> {$highestVersion}\n";
         }
 
@@ -118,12 +120,14 @@ if (count($uniqueVersions) === 1) {
             if (!file_exists($file)) continue;
 
             $content = file_get_contents($file);
-            $content = preg_replace(
+            $updated = preg_replace(
                 '|<version>[^<]*</version>|',
                 "<version>{$highestVersion}</version>",
                 $content
             );
-            file_put_contents($file, $content);
+            if ($updated !== null) {
+                file_put_contents($file, $updated);
+            }
             echo "  Fixed: {$source} -> {$highestVersion}\n";
         }
 

cli/version_set_platform.php

@@ -152,7 +152,7 @@ if (in_array($platform, ['waas-component', 'joomla'], true)) {
             "<version>{$version}</version>",
             $content
         );
-        if ($updated !== $content) {
+        if ($updated !== null && $updated !== $content) {
             file_put_contents($file, $updated);
             $relPath = str_replace($root . '/', '', $file);
             echo "Joomla: {$relPath} → {$version}\n";