Merge "Introduce config var for moved-paragraph-detection threshold"

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 6ce9a66..f35715e 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -8301,6 +8301,20 @@ $wgUpdateRowsPerQuery = 100;
  */
 $wgExternalDiffEngine = false;
 
+/**
+ * wikidiff2 supports detection of changes in moved paragraphs.
+ * This setting controls the maximum number of paragraphs to compare before it bails out.
+ * Supported values:
+ * * 0: detection of moved paragraphs is disabled
+ * * int > 0: maximum number of paragraphs to compare
+ * Note: number of paragraph comparisons is in O(n^2).
+ * This setting is only effective if the wikidiff2 PHP/HHVM module is used as diffengine.
+ * See $wgExternalDiffEngine.
+ *
+ * @since 1.30
+ */
+$wgWikiDiff2MovedParagraphDetectionCutoff = 0;
+
 /**
  * Disable redirects to special pages and interwiki redirects, which use a 302
  * and have no "redirected from" link.

diff --git a/includes/diff/DifferenceEngine.php b/includes/diff/DifferenceEngine.php
index 0b58cc1..5f6974e 100644 (file)
--- a/includes/diff/DifferenceEngine.php
+++ b/includes/diff/DifferenceEngine.php
@@ -908,10 +908,35 @@ class DifferenceEngine extends ContextSource {
                        $wgExternalDiffEngine = false;
                }
 
+               // Better external diff engine, the 2 may some day be dropped
+               // This one does the escaping and segmenting itself
                if ( function_exists( 'wikidiff2_do_diff' ) && $wgExternalDiffEngine === false ) {
-                       # Better external diff engine, the 2 may some day be dropped
-                       # This one does the escaping and segmenting itself
-                       $text = wikidiff2_do_diff( $otext, $ntext, 2 );
+                       $wikidiff2Version = phpversion( 'wikidiff2' );
+                       if (
+                               $wikidiff2Version !== false &&
+                               version_compare( $wikidiff2Version, '0.3.0', '>=' )
+                       ) {
+                               $text = wikidiff2_do_diff(
+                                       $otext,
+                                       $ntext,
+                                       2,
+                                       $this->getConfig()->get( 'WikiDiff2MovedParagraphDetectionCutoff' )
+                               );
+                       } else {
+                               // Don't pass the 4th parameter for compatibility with older versions of wikidiff2
+                               $text = wikidiff2_do_diff(
+                                       $otext,
+                                       $ntext,
+                                       2
+                               );
+
+                               // Log a warning in case the configuration value is set to not silently ignore it
+                               if ( $this->getConfig()->get( 'WikiDiff2MovedParagraphDetectionCutoff' ) > 0 ) {
+                                       wfLogWarning( '$wgWikiDiff2MovedParagraphDetectionCutoff is set but has no
+                                               effect since the used version of WikiDiff2 does not support it.' );
+                               }
+                       }
+
                        $text .= $this->debug( 'wikidiff2' );
 
                        return $text;

diff --git a/tests/phan/stubs/wikidiff.php b/tests/phan/stubs/wikidiff.php
index 9bd5d8d..1015b0b 100644 (file)
--- a/tests/phan/stubs/wikidiff.php
+++ b/tests/phan/stubs/wikidiff.php
@@ -22,7 +22,8 @@
  * @param string $text1
  * @param string $text2
  * @param int $numContextLines
+ * @param int $movedParagraphDetectionCutoff
  * @return string
  */
-function wikidiff2_do_diff( $text1, $text2, $numContextLines ) {
+function wikidiff2_do_diff( $text1, $text2, $numContextLines, $movedParagraphDetectionCutoff = 0 ) {
 }