From 4c88e9d1ef196e286a82a3b68d1334b3966ed871 Mon Sep 17 00:00:00 2001
From: Sebastian Ramacher <sebastian+dev@ramacher.at>
Date: Fri, 22 Nov 2013 06:23:22 +0100
Subject: [PATCH] Make sure we do not underflow

---
 adjustment.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/adjustment.c b/adjustment.c
index b162419..af07009 100644
--- a/adjustment.c
+++ b/adjustment.c
@@ -69,7 +69,12 @@ position_to_page_number(zathura_document_t* document, double pos_x,
   unsigned int col = floor(pos_x * (double)doc_width  / (double)(cell_width + pad));
   unsigned int row = floor(pos_y * (double)doc_height / (double)(cell_height + pad));
 
-  return ncol * (row % nrow) + (col % ncol) - (c0 - 1);
+  unsigned int page = ncol * (row % nrow) + (col % ncol);
+  if (page < c0 - 1) {
+    return 0;
+  } else {
+    return page - (c0 - 1);
+  }
 }