clear user configured mime associations when updating

src/vs/base/common/mime.ts

@@ -22,10 +22,10 @@ export interface ITextMimeAssociation {
 	userConfigured?: boolean;
 }
 
-const registeredAssociations: ITextMimeAssociation[] = [];
+let registeredAssociations: ITextMimeAssociation[] = [];
 
 /**
- * Associate a text mime to the registry
+ * Associate a text mime to the registry.
  */
 export function registerTextMime(association: ITextMimeAssociation): void {
 
@@ -58,6 +58,17 @@ export function registerTextMime(association: ITextMimeAssociation): void {
 	}
 }
 
+/**
+ * Clear text mimes from the registry.
+ */
+export function clearTextMimes(onlyUserConfigured?: boolean): void {
+	if (!onlyUserConfigured) {
+		registeredAssociations = [];
+	} else {
+		registeredAssociations = registeredAssociations.filter(a => !a.userConfigured);
+	}
+}
+
 /**
  * Given a file, return the best matching mime type for it
  */

src/vs/workbench/parts/files/common/editors/fileAssociations.ts

@@ -39,6 +39,11 @@ export class FileAssociations implements IWorkbenchContribution {
 	}
 
 	private onConfigurationChange(configuration: IFilesConfiguration): void {
+
+		// Clear user configured mime associations
+		mime.clearTextMimes(true /* user configured */);
+
+		// Register based on settings
 		if (configuration.files && configuration.files.associations) {
 			Object.keys(configuration.files.associations).forEach(pattern => {
 				mime.registerTextMime({ mime: this.modeService.getMimeForMode(configuration.files.associations[pattern]), filepattern: pattern, userConfigured: true });