fix bundle mappings after remove and move in multiple sources

src/utils/Mappings.js

@@ -48,9 +48,7 @@ export default class Mappings {
 			originalCharIndex += 1;
 		}
 
-		this.pending = sourceIndex > 0
-			? [this.generatedCodeColumn, sourceIndex, loc.line, loc.column]
-			: null;
+		this.pending = null;
 	}
 
 	advance(str) {

test/MagicString.Bundle.js

@@ -666,4 +666,55 @@ var template = (function () {
 			assert.strictEqual(b.toString(), 'abcdef');
 		});
 	});
+
+	describe('mappings', () => {
+		it('should produce correct mappings after remove and move in multiple sources', () => {
+			const s1 = 'ABCDE';
+			const ms1 = new MagicString(s1, { filename: 'first' });
+
+			const s2 = 'VWXYZ';
+			const ms2 = new MagicString(s2, { filename: 'second' });
+
+			const bundle = new MagicString.Bundle();
+			bundle.addSource(ms1);
+			bundle.addSource(ms2);
+
+			ms1.remove(2,4);   // ABE
+			ms1.move(0, 1, 5); // BEA
+
+			ms2.remove(2,4);   // VWZ
+			ms2.move(0, 1, 5); // WZV
+
+			const map = bundle.generateMap({file: 'result', hires: true, includeContent: true});
+			const smc = new SourceMapConsumer(map);
+
+			const result1 = ms1.toString();
+			assert.strictEqual(result1, 'BEA');
+
+			const result2 = ms2.toString();
+			assert.strictEqual(result2, 'WZV');
+
+			assert.strictEqual(bundle.toString(), 'BEA\nWZV');
+
+			// B = B
+			// E = E
+			// A = A
+			let line = 1;
+			for (let i = 0; i < result1.length; i++) {
+				const loc = smc.originalPositionFor({ line, column: i });
+				assert.strictEqual(s1[loc.column], result1[i]);
+			}
+
+			// W = W
+			// Z = Z
+			// V = V
+			line = 2;
+			for (let i = 0; i < result2.length; i++) {
+				const loc = smc.originalPositionFor({ line, column: i });
+				assert.strictEqual(s2[loc.column], result2[i]);
+			}
+
+			assert.strictEqual(map.toString(), '{"version":3,"file":"result","sources":["first","second"],"sourcesContent":["ABCDE","VWXYZ"],"names":[],"mappings":"AAAC,CAAG,CAAJ;ACAC,CAAG,CAAJ"}');
+		});
+	});
 });