updates from pr feedback

Author: jtpetty

app/exec/extension/_lib/vsix-manifest-builder.ts

@@ -798,13 +798,15 @@ export class VsixManifestBuilder extends ManifestBuilder {
 			Object.keys(this.files).forEach(filePath => {
 				if (this.files[filePath].contentType) {
 					let partName = "/" + toZipItemName(this.files[filePath].partName);
-					contentTypes.Types.Override.push({
-						$: {
-							ContentType: this.files[filePath].contentType,
-							PartName: partName,
-						},
-					});
-					seenPartNames.add(partName);
+					if (!seenPartNames.has(partName)) {
+						contentTypes.Types.Override.push({
+							$: {
+								ContentType: this.files[filePath].contentType,
+								PartName: partName,
+							},
+						});
+						seenPartNames.add(partName);
+					}
 					if ((this.files[filePath] as any)._additionalPackagePaths) {
 						for (const additionalPath of (this.files[filePath] as any)._additionalPackagePaths) {							
 							let additionalPartName =  "/" + toZipItemName(additionalPath);

app/exec/extension/_lib/vsix-writer.ts

@@ -184,8 +184,10 @@ export class VsixWriter {
 					if (itemName.indexOf(" "))
 						if (!builder.files[path].content) {
 							let readFilePromise = promisify(readFile)(path).then(result => {
-								vsix.file(itemName, result);
-								seenPartNames.add(itemName);
+								if (!seenPartNames.has(itemName)) {
+									vsix.file(itemName, result);
+									seenPartNames.add(itemName);
+								}
 								if ((builder.files[path] as any)._additionalPackagePaths) {
 									for (const p of (builder.files[path] as any)._additionalPackagePaths) {
 										let additionalItemName = toZipItemName(p);
@@ -198,8 +200,10 @@ export class VsixWriter {
 							});
 							readFilePromises.push(readFilePromise);
 						} else {
-							vsix.file(itemName, builder.files[path].content);
-							seenPartNames.add(itemName);
+							if (!seenPartNames.has(itemName)) {
+								vsix.file(itemName, builder.files[path].content);
+								seenPartNames.add(itemName);
+							}
 							if ((builder.files[path] as any)._additionalPackagePaths) {
 								for (const p of (builder.files[path] as any)._additionalPackagePaths) {
 									let additionalItemName = toZipItemName(p);