From b9cf731dc495d3a721b4e503113751a24f17d2c3 Mon Sep 17 00:00:00 2001
From: Iulian Moraru <imoraru@mozilla.com>
Date: Tue, 11 May 2021 18:44:50 +0300
Subject: [PATCH] Backed out changeset 160daad53292 (bug 1710462) for causing
 browser chrome failures on browser_subdialogs.js. CLOSED TREE

---
 toolkit/modules/SubDialog.jsm | 32 ++++++++++++++------------------
 1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/toolkit/modules/SubDialog.jsm b/toolkit/modules/SubDialog.jsm
index f2bbac754307..07e0ff36c2cd 100644
--- a/toolkit/modules/SubDialog.jsm
+++ b/toolkit/modules/SubDialog.jsm
@@ -362,19 +362,13 @@ SubDialog.prototype = {
     let oldResizeBy = this._frame.contentWindow.resizeBy;
     this._frame.contentWindow.resizeBy = (resizeByWidth, resizeByHeight) => {
       // Only handle resizeByHeight currently.
-      let frameHeight = this._overlay.parentNode.style.getPropertyValue(
-        "--inner-height"
-      );
-      if (frameHeight) {
-        frameHeight = parseFloat(frameHeight, 10);
-      } else {
-        frameHeight = this._frame.clientHeight;
-      }
+      let frameHeight = this._frame.clientHeight;
       let boxMinHeight = parseFloat(
         this._window.getComputedStyle(this._box).minHeight,
         10
       );
 
+      this._frame.style.height = frameHeight + resizeByHeight + "px";
       this._box.style.minHeight = boxMinHeight + resizeByHeight + "px";
 
       this._overlay.parentNode.style.setProperty(
@@ -565,8 +559,10 @@ SubDialog.prototype = {
 
     // Now check if the frame height we calculated is possible at this window size,
     // accounting for titlebar, padding/border and some spacing.
-    let frameOverhead = frameSizeDifference + (this._titleBar ? 30 : 0);
-    let maxHeight = this._window.innerHeight - frameOverhead;
+    let maxHeight =
+      this._window.innerHeight -
+      frameSizeDifference -
+      (this._titleBar ? 30 : 0);
     // Do this with a frame height in pixels...
     let comparisonFrameHeight;
     if (frameHeight.endsWith("em")) {
@@ -595,6 +591,7 @@ SubDialog.prototype = {
       // contents scroll. The class is set on the "dialog" element, unless a
       // content pane exists, which is usually the case when the "window"
       // element is used to implement the subdialog instead.
+      frameHeight = maxHeight + "px";
       frameMinHeight = maxHeight + "px";
 
       if (contentPane) {
@@ -606,15 +603,14 @@ SubDialog.prototype = {
       }
     }
 
+    this._frame.style.height = frameHeight;
     this._overlay.parentNode.style.setProperty("--inner-height", frameHeight);
-    this._frame.style.height = `min(
-      calc(100vh - ${frameOverhead}px),
-      var(--inner-height, ${frameHeight})
-    )`;
-    this._box.style.minHeight = `calc(
-      ${boxVerticalBorder + titleBarHeight + frameVerticalMargin}px +
-      ${frameMinHeight}
-    )`;
+    this._box.style.minHeight =
+      "calc(" +
+      (boxVerticalBorder + titleBarHeight + frameVerticalMargin) +
+      "px + " +
+      frameMinHeight +
+      ")";
   },
 
   _onResize(mutations) {