Report unterminated double-quoted values instead of dropping them

src/Parser/Lines.php

@@ -43,6 +43,13 @@ public static function process(array $lines)
             }
         }
 
+        // The input ended while still within a multiline value. Emit what was
+        // buffered, so that the parser reports the missing closing quote,
+        // instead of discarding this entry and every line that followed it.
+        if ($multiline) {
+            $output[] = \implode("\n", $multilineBuffer);
+        }
+
         return $output;
     }
 

tests/Dotenv/DotenvTest.php

@@ -6,6 +6,7 @@
 
 use Dotenv\Dotenv;
 use Dotenv\Exception\InvalidEncodingException;
+use Dotenv\Exception\InvalidFileException;
 use Dotenv\Exception\InvalidPathException;
 use Dotenv\Loader\Loader;
 use Dotenv\Parser\Parser;
@@ -450,6 +451,30 @@ public function testDotenvParseMultilineContainingHash()
         );
     }
 
+    public function testDotenvParseUnterminatedDoubleQuote()
+    {
+        $this->expectException(InvalidFileException::class);
+        $this->expectExceptionMessage('Encountered a missing closing quote at ["bar].');
+
+        Dotenv::parse('FOO="bar');
+    }
+
+    public function testDotenvParseUnterminatedDoubleQuoteDoesNotSwallowLaterLines()
+    {
+        $this->expectException(InvalidFileException::class);
+        $this->expectExceptionMessage('Encountered a missing closing quote at ["oops].');
+
+        Dotenv::parse("A=\"oops\nB=keep");
+    }
+
+    public function testDotenvParseUnterminatedDoubleQuoteMatchesSingleQuote()
+    {
+        $this->expectException(InvalidFileException::class);
+        $this->expectExceptionMessage('Encountered a missing closing quote at [\'bar].');
+
+        Dotenv::parse("FOO='bar");
+    }
+
     public function testDotenvParseEmptyCase()
     {
         $output = Dotenv::parse('');