improve the check, avoid strlen on NULLphp-7.0.10RC1

(cherry picked from commit 9667ee4f72c7dafce993b71104a52beb7c3aff15)

1 files changed, 4 insertions, 4 deletions

diff --git a/ext/exif/exif.c b/ext/exif/exif.c
index a7452184f9..611b1067cc 100644
--- a/ext/exif/exif.c
+++ b/ext/exif/exif.c
@@ -1702,11 +1702,11 @@ static void exif_iif_add_value(image_info_type *image_info, int section_index, c
 			if (!length)
 				break;
 		case TAG_FMT_UNDEFINED:
-			if (tag == TAG_MAKER_NOTE) {
-				length = MIN(length, strlen(value));
-			}
-
 			if (value) {
+				if (tag == TAG_MAKER_NOTE) {
+					length = MIN(length, strlen(value));
+				}
+
 				/* do not recompute length here */
 				info_value->s = estrndup(value, length);
 				info_data->length = length;