From 7e6a70af4433847a7ef740489ab6bfad4b09861a Mon Sep 17 00:00:00 2001
From: BJJ <bianjunjie1981@hotmail.com>
Date: Sat, 20 May 2023 19:12:01 +0800
Subject: [PATCH] Improve detection of jp2 filename extensions #3674

---
 lib/output.js    | 4 ++--
 test/unit/jp2.js | 7 +++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index 2268ab3d3..146f2a652 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -29,7 +29,7 @@ const formats = new Map([
   ['jxl', 'jxl']
 ]);
 
-const jp2Regex = /\.jp[2x]|j2[kc]$/i;
+const jp2Regex = /\.(jp[2x]|j2[kc])$/i;
 
 const errJp2Save = () => new Error('JP2 output requires libvips with support for OpenJPEG');
 
@@ -75,7 +75,7 @@ function toFile (fileOut, callback) {
     err = new Error('Missing output file path');
   } else if (is.string(this.options.input.file) && path.resolve(this.options.input.file) === path.resolve(fileOut)) {
     err = new Error('Cannot use same file for input and output');
-  } else if (jp2Regex.test(fileOut) && !this.constructor.format.jp2k.output.file) {
+  } else if (jp2Regex.test(path.extname(fileOut)) && !this.constructor.format.jp2k.output.file) {
     err = errJp2Save();
   }
   if (err) {
diff --git a/test/unit/jp2.js b/test/unit/jp2.js
index 79efac6d2..c70f1543a 100644
--- a/test/unit/jp2.js
+++ b/test/unit/jp2.js
@@ -25,6 +25,13 @@ describe('JP2 output', () => {
         /JP2 output requires libvips with support for OpenJPEG/
       )
     );
+
+    it('File with JP2-like suffix should not fail due to missing OpenJPEG', () => {
+      const output = fixtures.path('output.failj2c');
+      return assert.doesNotReject(
+        async () => sharp(fixtures.inputPngWithOneColor).toFile(output)
+      );
+    });
   } else {
     it('JP2 Buffer to PNG Buffer', () => {
       sharp(fs.readFileSync(fixtures.inputJp2))