From 3e238e8ba76850ce5050364dd69d7ad1fcabcaeb Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 23 Jan 2020 16:07:57 +0530
Subject: [PATCH] Comments editor: Fix a regression when switching between
 normal and source view

---
 src/calibre/gui2/comments_editor.py    |  4 ++--
 src/calibre/gui2/tweak_book/widgets.py | 15 ++-------------
 src/calibre/gui2/widgets2.py           | 17 +++++++++++++++++
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/src/calibre/gui2/comments_editor.py b/src/calibre/gui2/comments_editor.py
index 7dcc909d6a..79c0952fc2 100644
--- a/src/calibre/gui2/comments_editor.py
+++ b/src/calibre/gui2/comments_editor.py
@@ -25,6 +25,7 @@ from calibre.ebooks.chardet import xml_to_unicode
 from calibre.gui2 import NO_URL_FORMATTING, choose_files, error_dialog, gprefs
 from calibre.gui2.book_details import css
 from calibre.gui2.widgets import LineEditECM
+from calibre.gui2.widgets2 import to_plain_text
 from calibre.utils.config import tweaks
 from calibre.utils.imghdr import what
 from polyglot.builtins import filter, iteritems, itervalues, unicode_type
@@ -1138,8 +1139,7 @@ class Editor(QWidget):  # {{{
                 self.wyswyg_dirty = False
         elif index == 0:  # changing to wyswyg
             if self.source_dirty:
-                from calibre.gui2.tweak_book.widgets import PlainTextEdit
-                self.editor.html = PlainTextEdit.toPlainText(self.code_edit)
+                self.editor.html = to_plain_text(self.code_edit)
                 self.source_dirty = False
 
     @property
diff --git a/src/calibre/gui2/tweak_book/widgets.py b/src/calibre/gui2/tweak_book/widgets.py
index 6eed3d02b0..1135135fff 100644
--- a/src/calibre/gui2/tweak_book/widgets.py
+++ b/src/calibre/gui2/tweak_book/widgets.py
@@ -22,14 +22,13 @@ from calibre.ebooks.oeb.polish.cover import get_raster_cover_name
 from calibre.ebooks.oeb.polish.utils import lead_text, guess_type
 from calibre.gui2 import error_dialog, choose_files, choose_save_file, info_dialog, choose_images
 from calibre.gui2.tweak_book import tprefs, current_container
-from calibre.gui2.widgets2 import Dialog as BaseDialog, HistoryComboBox
+from calibre.gui2.widgets2 import Dialog as BaseDialog, HistoryComboBox, to_plain_text, PARAGRAPH_SEPARATOR
 from calibre.utils.icu import primary_sort_key, sort_key, primary_contains, numeric_sort_key
 from calibre.utils.matcher import get_char, Matcher
 from calibre.gui2.complete2 import EditWithComplete
 from polyglot.builtins import iteritems, unicode_type, zip, getcwd, filter as ignore_me
 
 ROOT = QModelIndex()
-PARAGRAPH_SEPARATOR = '\u2029'
 ignore_me
 
 
@@ -1199,17 +1198,7 @@ class PlainTextEdit(QPlainTextEdit):  # {{{
         self.syntax = None
 
     def toPlainText(self):
-        # QPlainTextEdit's toPlainText implementation replaces nbsp with normal
-        # space, so we re-implement it using QTextCursor, which does not do
-        # that
-        c = self.textCursor()
-        c.clearSelection()
-        c.movePosition(c.Start)
-        c.movePosition(c.End, c.KeepAnchor)
-        ans = c.selectedText().replace(PARAGRAPH_SEPARATOR, '\n')
-        # QTextCursor pads the return value of selectedText with null bytes if
-        # non BMP characters such as 0x1f431 are present.
-        return ans.rstrip('\0')
+        return to_plain_text(self)
 
     def selected_text_from_cursor(self, cursor):
         return unicodedata.normalize('NFC', unicode_type(cursor.selectedText()).replace(PARAGRAPH_SEPARATOR, '\n').rstrip('\0'))
diff --git a/src/calibre/gui2/widgets2.py b/src/calibre/gui2/widgets2.py
index 9f2401beb4..c489597e35 100644
--- a/src/calibre/gui2/widgets2.py
+++ b/src/calibre/gui2/widgets2.py
@@ -511,6 +511,23 @@ class ScrollingTabWidget(QTabWidget):
         return QTabWidget.addTab(self, self.wrap_widget(page), *args)
 
 
+PARAGRAPH_SEPARATOR = '\u2029'
+
+
+def to_plain_text(self):
+    # QPlainTextEdit's toPlainText implementation replaces nbsp with normal
+    # space, so we re-implement it using QTextCursor, which does not do
+    # that
+    c = self.textCursor()
+    c.clearSelection()
+    c.movePosition(c.Start)
+    c.movePosition(c.End, c.KeepAnchor)
+    ans = c.selectedText().replace(PARAGRAPH_SEPARATOR, '\n')
+    # QTextCursor pads the return value of selectedText with null bytes if
+    # non BMP characters such as 0x1f431 are present.
+    return ans.rstrip('\0')
+
+
 if __name__ == '__main__':
     from calibre.gui2 import Application
     app = Application([])