From e4a333a9805a1668860f0a5d134772e21e7904fb Mon Sep 17 00:00:00 2001
From: NiLuJe <ninuje@gmail.com>
Date: Tue, 15 Jun 2021 18:11:04 +0200
Subject: [PATCH] KOptInterface: Keep returning nil in get*Boxes when we don't
 actually get any boxes

Exposed by #7624, but we were arguably putting garbage in the Cache
before that anyway, so, it w<asn't all that great either ;p.

Fix #7850
---
 frontend/document/koptinterface.lua | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/frontend/document/koptinterface.lua b/frontend/document/koptinterface.lua
index 387a96ea8..be6a991d9 100644
--- a/frontend/document/koptinterface.lua
+++ b/frontend/document/koptinterface.lua
@@ -516,6 +516,9 @@ function KoptInterface:getReflowedTextBoxes(doc, pageno)
             --kc:setDebug()
             local fullwidth, fullheight = kc:getPageDim()
             local boxes, nr_word = kc:getReflowedWordBoxes("dst", 0, 0, fullwidth, fullheight)
+            if not boxes then
+                return nil
+            end
             DocCache:insert(hash, CacheItem:new{ rfpgboxes = boxes, size = 192 * nr_word }) -- estimation
             return boxes
         end
@@ -541,6 +544,9 @@ function KoptInterface:getNativeTextBoxes(doc, pageno)
             --kc:setDebug()
             local fullwidth, fullheight = kc:getPageDim()
             local boxes, nr_word = kc:getNativeWordBoxes("dst", 0, 0, fullwidth, fullheight)
+            if not boxes then
+                return nil
+            end
             DocCache:insert(hash, CacheItem:new{ nativepgboxes = boxes, size = 192 * nr_word }) -- estimation
             return boxes
         end
@@ -569,8 +575,11 @@ function KoptInterface:getReflowedTextBoxesFromScratch(doc, pageno)
             local kc = self:createContext(doc, pageno)
             kc:copyDestBMP(reflowed_kc)
             local boxes, nr_word = kc:getNativeWordBoxes("dst", 0, 0, fullwidth, fullheight)
-            DocCache:insert(hash, CacheItem:new{ scratchrfpgboxes = boxes, size = 192 * nr_word }) -- estimation
             kc:free()
+            if not boxes then
+                return nil
+            end
+            DocCache:insert(hash, CacheItem:new{ scratchrfpgboxes = boxes, size = 192 * nr_word }) -- estimation
             return boxes
         end
     else