From 22acded7a21346826bcc1501f23fe6bf29faa4f2 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 30 Jul 2020 13:42:09 +0530
Subject: [PATCH] Viewer: Fix using a very small font step size not working.
 Fixes #1888609 [If I reduce font size below 10, then keyboard shortcut to
 increase font size stops
 working](https://bugs.launchpad.net/calibre/+bug/1888609)

---
 src/pyj/read_book/prefs/font_size.pyj | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/pyj/read_book/prefs/font_size.pyj b/src/pyj/read_book/prefs/font_size.pyj
index 5de1076b51..40ebe2e33c 100644
--- a/src/pyj/read_book/prefs/font_size.pyj
+++ b/src/pyj/read_book/prefs/font_size.pyj
@@ -49,6 +49,8 @@ def change_font_size_by(frac):
     sd = get_session_data()
     sz = sd.get('base_font_size')
     amt = sz * frac
+    if abs(amt) < 1:
+        amt = -1 if amt < 0 else 1
     nsz = int(sz + amt)
     nsz = max(MIN_FONT_SIZE, min(nsz, MAX_FONT_SIZE))
     change_font_size(nsz)