Give the content a min height again

Hopefully avoid unnoticed widget height changes by requesting a measure on a no-op flush

FIX: Make the context menu work when clicking below the content in a fixed-height
editor.

Closes codemirror/dev#1277

src/domobserver.ts

@@ -371,7 +371,10 @@ export class DOMObserver {
     if (readSelection) this.readSelectionRange()
 
     let domChange = this.readChange()
-    if (!domChange) return false
+    if (!domChange) {
+      this.view.requestMeasure()
+      return false
+    }
     let startState = this.view.state
     let handled = applyDOMChange(this.view, domChange)
     // The view wasn't updated

src/input.ts

@@ -64,22 +64,6 @@ export class InputState {
 
   constructor(readonly view: EditorView) {
     this.handleEvent = this.handleEvent.bind(this)
-    view.scrollDOM.addEventListener("mousedown", (event: MouseEvent) => {
-      if (event.target == view.scrollDOM && event.clientY > view.contentDOM.getBoundingClientRect().bottom) {
-        this.runHandlers("mousedown", event)
-        if (!event.defaultPrevented && event.button == 2) {
-          // Make sure the content covers the entire scroller height, in order
-          // to catch a native context menu click below it
-          let start = view.contentDOM.style.minHeight
-          view.contentDOM.style.minHeight = "100%"
-          setTimeout(() => view.contentDOM.style.minHeight = start, 200)
-        }
-      }
-    })
-    view.scrollDOM.addEventListener("drop", (event: DragEvent) => {
-      if (event.target == view.scrollDOM && event.clientY > view.contentDOM.getBoundingClientRect().bottom)
-        this.runHandlers("drop", event)
-    })
     this.notifiedFocused = view.hasFocus
     // On Safari adding an input event handler somehow prevents an
     // issue where the composition vanishes when you press enter.

src/theme.ts

@@ -59,6 +59,7 @@ export const baseTheme = buildTheme("." + baseThemeID, {
     whiteSpace: "pre",
     wordWrap: "normal", // https://github.com/codemirror/dev/issues/456
     boxSizing: "border-box",
+    minHeight: "100%",
 
     padding: "4px 0",
     outline: "none",