From e1033620c9c8f6d8bf45befd7ddf2e2e81c3ca76 Mon Sep 17 00:00:00 2001
From: David Schwartz <davidjoelschwartz@gmail.com>
Date: Thu, 25 Jul 2013 11:38:05 -0700
Subject: [PATCH 1/3] Fix prevMissing.

---
 .../containers/ripple_RangeSet.cpp            | 22 ++++++++++++++-----
 src/cpp/ripple/LedgerMaster.cpp               |  2 +-
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/modules/ripple_basics/containers/ripple_RangeSet.cpp b/modules/ripple_basics/containers/ripple_RangeSet.cpp
index 30b0fcafbd..2482d5b5c7 100644
--- a/modules/ripple_basics/containers/ripple_RangeSet.cpp
+++ b/modules/ripple_basics/containers/ripple_RangeSet.cpp
@@ -66,7 +66,6 @@ uint32 RangeSet::getPrev (uint32 v) const
             return it.second;
 
         if (contains (it, v + 1))
-            return v - 1;
     }
     return RangeSetAbsent;
 }
@@ -74,15 +73,26 @@ uint32 RangeSet::getPrev (uint32 v) const
 uint32 RangeSet::prevMissing (uint32 v) const
 {
     // largest number not in the set that is less than the given number
-    BOOST_FOREACH (const value_type & it, mRanges)
+    uint32 result = RangeSetAbsent;
+
+    BOOST_REVERSE_FOREACH (const value_type & it, mRanges)
     {
         if (contains (it, v))
-            return it.first - 1;
+        {
+            if (it.first == 0)
+                result = RangeSetAbsent;
+            else
+                result = it.first - 1;
+        }
 
-        if (it.first > v)
-            return v + 1;
+        if (v > it.second)
+        {
+            if (v == it.second + 1)
+                result = it.first - 1;
+            result = v - 1;
+        }
     }
-    return RangeSetAbsent;
+    return result;
 }
 
 void RangeSet::setValue (uint32 v)
diff --git a/src/cpp/ripple/LedgerMaster.cpp b/src/cpp/ripple/LedgerMaster.cpp
index 7cfff58c15..359fa246f2 100644
--- a/src/cpp/ripple/LedgerMaster.cpp
+++ b/src/cpp/ripple/LedgerMaster.cpp
@@ -225,7 +225,7 @@ bool LedgerMaster::getValidatedRange (uint32& minVal, uint32& maxVal)
     minVal = mCompleteLedgers.prevMissing (maxVal);
 
     if (minVal == RangeSet::RangeSetAbsent)
-        minVal = 0;
+        minVal = maxVal;
     else
         ++minVal;
 

From 05ee52a70dda4b182ec236fba1cfbad7a41c1368 Mon Sep 17 00:00:00 2001
From: David Schwartz <davidjoelschwartz@gmail.com>
Date: Thu, 25 Jul 2013 11:56:39 -0700
Subject: [PATCH 2/3] Clean fix.

---
 .../containers/ripple_RangeSet.cpp            | 27 +++++++++----------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/modules/ripple_basics/containers/ripple_RangeSet.cpp b/modules/ripple_basics/containers/ripple_RangeSet.cpp
index 2482d5b5c7..be3d29733b 100644
--- a/modules/ripple_basics/containers/ripple_RangeSet.cpp
+++ b/modules/ripple_basics/containers/ripple_RangeSet.cpp
@@ -73,26 +73,23 @@ uint32 RangeSet::getPrev (uint32 v) const
 uint32 RangeSet::prevMissing (uint32 v) const
 {
     // largest number not in the set that is less than the given number
-    uint32 result = RangeSetAbsent;
 
-    BOOST_REVERSE_FOREACH (const value_type & it, mRanges)
+    // Nothing before zero
+    if (v == 0)
+        return RangeSetAbsent;
+
+    BOOST_FOREACH (const value_type & it, mRanges)
     {
-        if (contains (it, v))
-        {
+        if (contains (it, v - 1))
+        { // We have (v-1) in the set
             if (it.first == 0)
-                result = RangeSetAbsent;
-            else
-                result = it.first - 1;
-        }
-
-        if (v > it.second)
-        {
-            if (v == it.second + 1)
-                result = it.first - 1;
-            result = v - 1;
+                return RangeSetAbent;
+            return it.first - 1;
         }
     }
-    return result;
+
+    // We don't have (v-1), so v-1 is it
+    return v - 1;
 }
 
 void RangeSet::setValue (uint32 v)

From 1e3ee9bbf8d6839a6219d87b6693c756b7b510ed Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Thu, 25 Jul 2013 07:00:35 -0700
Subject: [PATCH 3/3] Fix compile error, add unit test for prevMissing

---
 .../containers/ripple_RangeSet.cpp            | 41 +++++++++++++++++--
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/modules/ripple_basics/containers/ripple_RangeSet.cpp b/modules/ripple_basics/containers/ripple_RangeSet.cpp
index be3d29733b..8c5a8b460b 100644
--- a/modules/ripple_basics/containers/ripple_RangeSet.cpp
+++ b/modules/ripple_basics/containers/ripple_RangeSet.cpp
@@ -66,6 +66,7 @@ uint32 RangeSet::getPrev (uint32 v) const
             return it.second;
 
         if (contains (it, v + 1))
+            return v - 1;
     }
     return RangeSetAbsent;
 }
@@ -83,7 +84,7 @@ uint32 RangeSet::prevMissing (uint32 v) const
         if (contains (it, v - 1))
         { // We have (v-1) in the set
             if (it.first == 0)
-                return RangeSetAbent;
+                return RangeSetAbsent;
             return it.first - 1;
         }
     }
@@ -189,6 +190,23 @@ void RangeSet::simplify ()
     }
 }
 
+static RangeSet createPredefinedRangeSet ()
+{
+    RangeSet set;
+
+    // Set will include:
+    // [ 0, 5]
+    // [10,15]
+    // [20,25]
+    // etc...
+
+    for (int i = 0; i < 10; ++i)
+        set.setRange (10 * i, 10 * i + 5);
+
+    return set;
+}
+
+
 BOOST_AUTO_TEST_SUITE (RangeSet_suite)
 
 BOOST_AUTO_TEST_CASE (RangeSet_test)
@@ -214,6 +232,23 @@ BOOST_AUTO_TEST_CASE (RangeSet_test)
     WriteLog (lsTRACE, RangeSet) << "RangeSet test complete";
 }
 
-BOOST_AUTO_TEST_SUITE_END ()
+BOOST_AUTO_TEST_CASE (RangeSetPrevMissing_test)
+{
+    RangeSet const set = createPredefinedRangeSet ();
 
-// vim:ts=4
+    for (int i = 0; i < 100; ++i)
+    {
+        int const oneBelowRange = (10*(i/10))-1;
+
+        int const expectedPrevMissing =
+            ((i % 10) > 6) ? (i-1) : oneBelowRange;
+
+        bool const pass = set.prevMissing (i) == expectedPrevMissing;
+
+        BOOST_REQUIRE (pass);
+
+        assert (pass);
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END ()