encoding - only allow to detect UTF8 automatically

Benjamin Pasero · Benjamin Pasero · commit 98ccdc7ba4af · 2019-12-05T10:35:27.000+01:00
diff --git a/src/vs/base/node/encoding.ts b/src/vs/base/node/encoding.ts
@@ -199,6 +199,13 @@ export function detectEncodingByBOMFromBuffer(buffer: Buffer | VSBuffer | null,
 	return null;
 }
 
+// we explicitly ignore a specific set of encodings from auto guessing
+// - ASCII: we never want this encoding (most UTF-8 files would happily detect as
+//          ASCII files and then you could not type non-ASCII characters anymore)
+// - UTF-16: we have our own detection logic for UTF-16
+// - UTF-32: we do not support this encoding in VSCode
+const IGNORE_ENCODINGS = ['ascii', 'utf-16', 'utf-32'];
+
 /**
  * Guesses the encoding from buffer.
  */
@@ -210,15 +217,9 @@ async function guessEncodingByBuffer(buffer: Buffer): Promise<string | null> {
 		return null;
 	}
 
-	// Ignore 'ascii' as guessed encoding because that
-	// is almost never what we want, rather fallback
-	// to the configured encoding then. Otherwise,
-	// opening a ascii-only file with auto guessing
-	// enabled will put the file into 'ascii' mode
-	// and thus typing any special characters is
-	// not possible anymore.
-	if (guessed.encoding.toLowerCase() === 'ascii') {
-		return null;
+	const enc = guessed.encoding.toLowerCase();
+	if (0 <= IGNORE_ENCODINGS.indexOf(enc)) {
+		return null; // see comment above why we ignore some encodings
 	}
 
 	return toIconvLiteEncoding(guessed.encoding);
