From: Kornel Benko <kornel@lyx.org>
Date: Tue, 27 Nov 2018 18:10:27 +0000 (+0100)
Subject: FindAdv: Eliminate a corner case in the binary search
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=703000a1a565ea612196dc0092f4b35d5eb4dd28;p=features.git

FindAdv: Eliminate a corner case in the binary search

Given the regex 'r.*r\b' and a string
"abc regular something cursor currently"
we expect to find "regular something cursor".
But while searching we may be confronted with input
"regular something cursor curr"
and so the searched string would be seen longer.
---

diff --git a/src/lyxfind.cpp b/src/lyxfind.cpp
index 35be0d0143..378b1c1d02 100644
--- a/src/lyxfind.cpp
+++ b/src/lyxfind.cpp
@@ -2679,26 +2679,28 @@ int findAdvFinalize(DocIterator & cur, MatchStringAdv const & match)
             len = 0;
         }
 	else {
-          int minl = 1;
-          int maxl = cur.lastpos() - cur.pos();
-          // Greedy behaviour while matching regexps
-          while (maxl > minl) {
-            int actual_match = match(cur, len);
-            if (actual_match == max_match) {
-              maxl = len;
-              len = (int)((maxl + minl)/2);
-            }
-            else if (actual_match < max_match) {
-              minl = len + 1;
-              len = (int)((maxl + minl)/2);
-            }
-            else {
-              // cannot happen, but in case of
-              LYXERR0("????");
-              max_match = actual_match;
-            }
-          }
-        }
+	  int minl = 1;
+	  int maxl = cur.lastpos() - cur.pos();
+	  // Greedy behaviour while matching regexps
+	  while (maxl > minl) {
+	    int actual_match = match(cur, len);
+	    if (actual_match >= max_match) {
+	      // actual_match > max_match _can_ happen,
+	      // if the search area splits
+	      // some following word so that the regex
+	      // (e.g. 'r.*r\b' matches 'r' from the middle of the
+	      // splitted word)
+	      // This means, the len value is too big
+	      maxl = len;
+	      len = (int)((maxl + minl)/2);
+	    }
+	    else {
+	      // (actual_match < max_match)
+	      minl = len + 1;
+	      len = (int)((maxl + minl)/2);
+	    }
+	  }
+	}
 	return len;
 }