From: Thiemo Kreuz <thiemo.kreuz@wikimedia.de>
Date: Tue, 26 Nov 2019 08:54:05 +0000 (+0100)
Subject: media: Log and fail gracefully on invalid EXIF coordinates
X-Git-Tag: 1.31.6~3
X-Git-Url: http://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=commitdiff_plain;h=4b9317c97a9a09ef3fe58e2013d83aeb47daf064

media: Log and fail gracefully on invalid EXIF coordinates

The $coord value is a value extracted from the EXIF section of an
image file. We expect it to be a float, but there is no guarantee this
is the case. It could, for example, be an empty string.

I suggest this trivial fix. It does have the following effects:
* Instead of logging a PHP notice when floor() hits something that is
  not a number, I try to log something that's more useful for later,
  more in-depth debugging. Note this log call isn't necessarily meant
  to stay, but to find an even better fix for this issue.
* I return the string as it is. If it's "foo", the user will see "foo"
  instead of "0° 0′ 0″ N", which wasn't helpful.

Also note how wrong and misleading the PHPDoc block for this function
was.

Bug: T226751
Change-Id: I1ca98728de4113ee1ae4362bd3e62b425d589388
(cherry picked from commit f6787ede2db29fcc2c1923e23eaa2e9bf86522a1)
---

diff --git a/includes/media/FormatMetadata.php b/includes/media/FormatMetadata.php
index 6cb33ac480..2a5a56f60e 100644
--- a/includes/media/FormatMetadata.php
+++ b/includes/media/FormatMetadata.php
@@ -1400,11 +1400,16 @@ class FormatMetadata extends ContextSource {
 	 * Format a coordinate value, convert numbers from floating point
 	 * into degree minute second representation.
 	 *
-	 * @param int $coord Degrees, minutes and seconds
-	 * @param string $type Latitude or longitude (for if its a NWS or E)
-	 * @return mixed A floating point number or whatever we were fed
+	 * @param float|string $coord Expected to be a number or numeric string in degrees
+	 * @param string $type "latitude" or "longitude"
+	 * @return string
 	 */
 	private function formatCoords( $coord, $type ) {
+		if ( !is_numeric( $coord ) ) {
+			wfDebugLog( 'exif', __METHOD__ . ": \"$coord\" is not a number" );
+			return (string)$coord;
+		}
+
 		$ref = '';
 		if ( $coord < 0 ) {
 			$nCoord = -$coord;
@@ -1414,7 +1419,7 @@ class FormatMetadata extends ContextSource {
 				$ref = 'W';
 			}
 		} else {
-			$nCoord = $coord;
+			$nCoord = (float)$coord;
 			if ( $type === 'latitude' ) {
 				$ref = 'N';
 			} elseif ( $type === 'longitude' ) {
@@ -1423,13 +1428,14 @@ class FormatMetadata extends ContextSource {
 		}
 
 		$deg = floor( $nCoord );
-		$min = floor( ( $nCoord - $deg ) * 60.0 );
-		$sec = round( ( ( $nCoord - $deg ) - $min / 60 ) * 3600, 2 );
+		$min = floor( ( $nCoord - $deg ) * 60 );
+		$sec = round( ( ( $nCoord - $deg ) * 60 - $min ) * 60, 2 );
 
 		$deg = $this->formatNum( $deg );
 		$min = $this->formatNum( $min );
 		$sec = $this->formatNum( $sec );
 
+		// Note the default message "$1° $2′ $3″ $4" ignores the 5th parameter
 		return $this->msg( 'exif-coordinate-format', $deg, $min, $sec, $ref, $coord )->text();
 	}