Force DejaVu Sans Mono font in terminal on Fedora

Fixes #35644

src/vs/workbench/parts/terminal/electron-browser/terminal.ts

@@ -8,6 +8,7 @@ import * as cp from 'child_process';
 import * as os from 'os';
 import * as platform from 'vs/base/common/platform';
 import * as processes from 'vs/base/node/processes';
+import { readFile, fileExists } from 'vs/base/node/pfs';
 
 export const TERMINAL_DEFAULT_SHELL_LINUX = !platform.isWindows ? (process.env.SHELL || 'sh') : 'sh';
 export const TERMINAL_DEFAULT_SHELL_OSX = !platform.isWindows ? (process.env.SHELL || 'sh') : 'sh';
@@ -21,3 +22,19 @@ export const TERMINAL_DEFAULT_SHELL_WINDOWS = isAtLeastWindows10 ? powerShellPat
 export interface ITerminalProcessFactory {
 	create(env: { [key: string]: string }): cp.ChildProcess;
 }
+
+if (platform.isLinux) {
+	fileExists('/etc/os-release').then(exists => {
+		if (!exists) {
+			return;
+		}
+		readFile('/etc/os-release').then(b => {
+			const contents = b.toString();
+			if (contents.indexOf('NAME=Fedora')) {
+				isFedora = true;
+			}
+		});
+	});
+}
+
+export let isFedora = false;
\ No newline at end of file

src/vs/workbench/parts/terminal/electron-browser/terminalConfigHelper.ts

@@ -14,6 +14,7 @@ import { IStorageService, StorageScope } from 'vs/platform/storage/common/storag
 import { ITerminalConfiguration, ITerminalConfigHelper, ITerminalFont, IShellLaunchConfig, IS_WORKSPACE_SHELL_ALLOWED_STORAGE_KEY } from 'vs/workbench/parts/terminal/common/terminal';
 import { TPromise } from 'vs/base/common/winjs.base';
 import Severity from 'vs/base/common/severity';
+import { isFedora } from 'vs/workbench/parts/terminal/electron-browser/terminal';
 
 interface IEditorConfiguration {
 	editor: IEditorOptions;
@@ -89,7 +90,15 @@ export class TerminalConfigHelper implements ITerminalConfigHelper {
 		const editorConfig = (<IEditorConfiguration>config).editor;
 		const terminalConfig = this.config;
 
-		const fontFamily = terminalConfig.fontFamily || editorConfig.fontFamily;
+		let fontFamily = terminalConfig.fontFamily || editorConfig.fontFamily;
+
+		// Work around bad font on Fedora
+		if (!terminalConfig.fontFamily) {
+			if (isFedora) {
+				fontFamily = '\'DejaVu Sans Mono\'';
+			}
+		}
+
 		let fontSize = this._toInteger(terminalConfig.fontSize, 0);
 		if (fontSize <= 0) {
 			fontSize = EDITOR_FONT_DEFAULTS.fontSize;