From 3c65731f38ead2d8c7045c8665daa7cb67a692a0 Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Sun, 27 Nov 2016 10:39:46 -0500
Subject: [PATCH] Sequence::InsertSilence gives strong guarantee

---
 src/Sequence.cpp | 11 ++++++-----
 src/Sequence.h   |  2 +-
 src/WaveClip.cpp |  6 +-----
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/Sequence.cpp b/src/Sequence.cpp
index bb0df2917..8e1e9dc0f 100644
--- a/src/Sequence.cpp
+++ b/src/Sequence.cpp
@@ -657,14 +657,16 @@ bool Sequence::SetSilence(sampleCount s0, sampleCount len)
    return Set(NULL, mSampleFormat, s0, len);
 }
 
-bool Sequence::InsertSilence(sampleCount s0, sampleCount len)
+void Sequence::InsertSilence(sampleCount s0, sampleCount len)
+// STRONG-GUARANTEE
 {
    // Quick check to make sure that it doesn't overflow
    if (Overflows((mNumSamples.as_double()) + (len.as_double())))
-      return false;
+      //THROW_INCONSISTENCY_EXCEPTION
+      ;
 
    if (len <= 0)
-      return true;
+      return;
 
    // Create a NEW track containing as much silence as we
    // need to insert, and then call Paste to do the insertion.
@@ -700,9 +702,8 @@ bool Sequence::InsertSilence(sampleCount s0, sampleCount len)
 
    sTrack.mNumSamples = pos;
 
+   // use STRONG-GUARANTEE
    Paste(s0, &sTrack);
-
-   return true;
 }
 
 bool Sequence::AppendAlias(const wxString &fullPath,
diff --git a/src/Sequence.h b/src/Sequence.h
index 192dc4f68..c416a4d48 100644
--- a/src/Sequence.h
+++ b/src/Sequence.h
@@ -129,7 +129,7 @@ class PROFILE_DLL_API Sequence final : public XMLTagHandler{
    void AppendBlockFile(const BlockFilePtr &blockFile);
 
    bool SetSilence(sampleCount s0, sampleCount len);
-   bool InsertSilence(sampleCount s0, sampleCount len);
+   void InsertSilence(sampleCount s0, sampleCount len);
 
    const std::shared_ptr<DirManager> &GetDirManager() { return mDirManager; }
 
diff --git a/src/WaveClip.cpp b/src/WaveClip.cpp
index 8d0f1f435..a224f2461 100644
--- a/src/WaveClip.cpp
+++ b/src/WaveClip.cpp
@@ -1631,11 +1631,7 @@ void WaveClip::InsertSilence(double t, double len)
    auto slen = (sampleCount)floor(len * mRate + 0.5);
 
    // use STRONG-GUARANTEE
-   if (!GetSequence()->InsertSilence(s0, slen))
-   {
-      wxASSERT(false);
-      return;
-   }
+   GetSequence()->InsertSilence(s0, slen);
 
    // use NOFAIL-GUARANTEE
    OffsetCutLines(t, len);