From a864703ce947c9a80e8076853b6ad313f7c000a7 Mon Sep 17 00:00:00 2001
From: anders_k <anders_k@212acab6-be3b-0410-9dea-997c60f758d6>
Date: Mon, 10 Mar 2014 00:06:42 +0000
Subject: [PATCH] Fix bug #1088 and try even harder by using substring if
 possible

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@6451 212acab6-be3b-0410-9dea-997c60f758d6
---
 Docs/src/history.but |  2 ++
 Source/strlist.cpp   | 18 ++++++++++--------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/Docs/src/history.but b/Docs/src/history.but
index 693b4822..e6350aa4 100644
--- a/Docs/src/history.but
+++ b/Docs/src/history.but
@@ -18,6 +18,8 @@ Released on ?, 2014
 
 \b Added P<, P<=, P=, P<>, P>= and P> LogicLib ptrdiff_t tests
 
+\b Try harder to find duplicate strings in string block (\W{http://sf.net/p/nsis/bugs/1088/}{bug #1088})
+
 \H{v3.0a2} 3.0 Alpha 2
 
 Released on December 24th, 2013
diff --git a/Source/strlist.cpp b/Source/strlist.cpp
index a8c217a3..6a850ebc 100644
--- a/Source/strlist.cpp
+++ b/Source/strlist.cpp
@@ -29,7 +29,7 @@ char* convert_processed_string_to_ansi(char *out, const TCHAR *in, WORD codepage
 static inline bool byte_rev_match(const void*ptr1, const void*ptr2, size_t cb)
 {
   char *p1 = (char*) ptr1, *p2 = (char*) ptr2;
-  if (cb) for(; --cb;) if (p1[cb] != p2[cb]) return false;
+  for(; cb--;) if (p1[cb] != p2[cb]) return false;
   return true;
 }
 
@@ -44,7 +44,7 @@ unsigned int ExeHeadStringList::getnum() const
   {
     for(;;)
     {
-      if (pos+=cb >= cbList) break;
+      if ((pos+=cb) >= cbList) break;
       cb = StrLenUTF16(p+=cb) + 1, ++num;
     }
   }
@@ -52,7 +52,7 @@ unsigned int ExeHeadStringList::getnum() const
   {
     for(;;)
     {
-      if (pos+=cb >= cbList) break;
+      if ((pos+=cb) >= cbList) break;
       cb = strlen(p+=cb) + 1, ++num;
     }
   }
@@ -134,26 +134,28 @@ unsigned int ExeHeadStringList::find(const void *ptr, unsigned int cchF, WORD co
     cbF = cbMB, find = (const wchar_t*) bufMB;
   }
 
-  unsigned int cbList = gettotalsize(), cb = 0, retval = -1, pos;
+  size_t cbList = gettotalsize(), cb = 0, retval = -1, pos;
   pos = 1 + !!m_wide, p += pos; // Skip empty string
   if (m_wide)
   {
     for(;;)
     {
-      if (pos+=cb >= cbList) break;
+      if ((pos+=cb) >= cbList) break;
       cb = (StrLenUTF16(p+=cb) + 1) * 2;
       if (cb < cbF) continue;
-      if (byte_rev_match(p,find,cbF)) { retval = pos / WIDEDIV; break; }
+      size_t cbOfs = cb - cbF;
+      if (byte_rev_match(p + cbOfs,find,cbF)) { retval = (pos + cbOfs) / WIDEDIV; break; }
     }
   }
   else
   {
     for(;;)
     {
-      if (pos+=cb >= cbList) break;
+      if ((pos+=cb) >= cbList) break;
       cb = (unsigned int) strlen(p+=cb) + 1;
       if (cb < cbF) continue;
-      if (byte_rev_match(p,find,cbF)) { retval = pos; break; }
+      size_t cbOfs = cb - cbF;
+      if (byte_rev_match(p + cbOfs,find,cbF)) { retval = (pos + cbOfs); break; }
     }
     if (ppBufMB) 
       *ppBufMB = bufMB;