From 6bb92c34fac889f0ca9667ed0d1c6cfda23a6938 Mon Sep 17 00:00:00 2001
From: Tsuda Kageyu <tsuda.kageyu@gmail.com>
Date: Fri, 20 Jan 2017 22:38:25 +0900
Subject: [PATCH] Ignore fake MPEG frame headers when seeking them.

---
 taglib/mpeg/mpegfile.cpp       |  57 ++++++++++++++++-----------------
 taglib/mpeg/mpegproperties.cpp |  29 +++--------------
 tests/data/garbage.mp3         | Bin 0 -> 8190 bytes
 tests/test_mpeg.cpp            |  33 ++++++++++++++-----
 4 files changed, 56 insertions(+), 63 deletions(-)
 create mode 100644 tests/data/garbage.mp3

diff --git a/taglib/mpeg/mpegfile.cpp b/taglib/mpeg/mpegfile.cpp
index c634eeb8..6860053b 100644
--- a/taglib/mpeg/mpegfile.cpp
+++ b/taglib/mpeg/mpegfile.cpp
@@ -346,55 +346,52 @@ void MPEG::File::setID3v2FrameFactory(const ID3v2::FrameFactory *factory)
 
 long MPEG::File::nextFrameOffset(long position)
 {
-  bool foundLastSyncPattern = false;
-
-  ByteVector buffer;
+  char frameSyncBytes[2] = {};
 
   while(true) {
     seek(position);
-    buffer = readBlock(bufferSize());
-
-    if(buffer.size() <= 0)
+    const ByteVector buffer = readBlock(bufferSize());
+    if(buffer.size() == 0)
       return -1;
 
-    if(foundLastSyncPattern && secondSynchByte(buffer[0]))
-      return position - 1;
-
-    for(unsigned int i = 0; i < buffer.size() - 1; i++) {
-      if(firstSyncByte(buffer[i]) && secondSynchByte(buffer[i + 1]))
-        return position + i;
+    for(unsigned int i = 0; i < buffer.size(); ++i) {
+      frameSyncBytes[0] = frameSyncBytes[1];
+      frameSyncBytes[1] = buffer[i];
+      if(firstSyncByte(frameSyncBytes[0]) && secondSynchByte(frameSyncBytes[1])) {
+        Header header(this, position + i - 1, true);
+        if(header.isValid())
+          return position + i - 1;
+      }
     }
 
-    foundLastSyncPattern = firstSyncByte(buffer[buffer.size() - 1]);
-    position += buffer.size();
+    position += bufferSize();
   }
 }
 
 long MPEG::File::previousFrameOffset(long position)
 {
-  bool foundFirstSyncPattern = false;
-  ByteVector buffer;
+  char frameSyncBytes[2] = {};
 
-  while (position > 0) {
-    long size = std::min<long>(position, bufferSize());
+  while(position > 0) {
+    const long size = std::min<long>(position, bufferSize());
     position -= size;
 
     seek(position);
-    buffer = readBlock(size);
-
-    if(buffer.size() <= 0)
-      break;
-
-    if(foundFirstSyncPattern && firstSyncByte(buffer[buffer.size() - 1]))
-      return position + buffer.size() - 1;
+    const ByteVector buffer = readBlock(bufferSize());
+    if(buffer.size() == 0)
+      return -1;
 
-    for(int i = buffer.size() - 2; i >= 0; i--) {
-      if(firstSyncByte(buffer[i]) && secondSynchByte(buffer[i + 1]))
-        return position + i;
+    for(int i = buffer.size() - 1; i >= 0; i--) {
+      frameSyncBytes[1] = frameSyncBytes[0];
+      frameSyncBytes[0] = buffer[i];
+      if(firstSyncByte(frameSyncBytes[0]) && secondSynchByte(frameSyncBytes[1])) {
+        Header header(this, position + i, true);
+        if(header.isValid())
+          return position + i + header.frameLength();
+      }
     }
-
-    foundFirstSyncPattern = secondSynchByte(buffer[0]);
   }
+
   return -1;
 }
 
diff --git a/taglib/mpeg/mpegproperties.cpp b/taglib/mpeg/mpegproperties.cpp
index 6e7bb823..d8b7bd50 100644
--- a/taglib/mpeg/mpegproperties.cpp
+++ b/taglib/mpeg/mpegproperties.cpp
@@ -157,23 +157,13 @@ void MPEG::Properties::read(File *file)
 {
   // Only the first valid frame is required if we have a VBR header.
 
-  long firstFrameOffset = file->firstFrameOffset();
+  const long firstFrameOffset = file->firstFrameOffset();
   if(firstFrameOffset < 0) {
     debug("MPEG::Properties::read() -- Could not find an MPEG frame in the stream.");
     return;
   }
 
-  Header firstHeader(file, firstFrameOffset);
-
-  while(!firstHeader.isValid()) {
-    firstFrameOffset = file->nextFrameOffset(firstFrameOffset + 1);
-    if(firstFrameOffset < 0) {
-      debug("MPEG::Properties::read() -- Could not find a valid first MPEG frame in the stream.");
-      return;
-    }
-
-    firstHeader = Header(file, firstFrameOffset);
-  }
+  const Header firstHeader(file, firstFrameOffset, false);
 
   // Check for a VBR header that will help us in gathering information about a
   // VBR stream.
@@ -207,24 +197,13 @@ void MPEG::Properties::read(File *file)
 
     // Look for the last MPEG audio frame to calculate the stream length.
 
-    long lastFrameOffset = file->lastFrameOffset();
+    const long lastFrameOffset = file->lastFrameOffset();
     if(lastFrameOffset < 0) {
       debug("MPEG::Properties::read() -- Could not find an MPEG frame in the stream.");
       return;
     }
 
-    Header lastHeader(file, lastFrameOffset, false);
-
-    while(!lastHeader.isValid()) {
-      lastFrameOffset = file->previousFrameOffset(lastFrameOffset);
-      if(lastFrameOffset < 0) {
-        debug("MPEG::Properties::read() -- Could not find a valid last MPEG frame in the stream.");
-        return;
-      }
-
-      lastHeader = Header(file, lastFrameOffset, false);
-    }
-
+    const Header lastHeader(file, lastFrameOffset, false);
     const long streamLength = lastFrameOffset - firstFrameOffset + lastHeader.frameLength();
     if(streamLength > 0)
       d->length = static_cast<int>(streamLength * 8.0 / d->bitrate + 0.5);
diff --git a/tests/data/garbage.mp3 b/tests/data/garbage.mp3
new file mode 100644
index 0000000000000000000000000000000000000000..730b74e7c2babe736acc8b5922e0a0fbc1f6f33f
GIT binary patch
literal 8190
zcmb8ubxd5ryEpJ<aar7pv)BTQYoR#Bt&2l(cP&<mv-si^cZcE>_u}qeC{Un+Q=HrW
z-n@U^o15GxIcHAhnaOuP$r&pKpRQzuwugCwwY2<9c}i4n@);SMt6zNr;dMKPDCZ@m
z>Kk8#MF8*9yB@BH_=^WbE_jJ>qRQi4%pI-j?57#FbPust9|`&o9<ko#CVo5YYe<ji
z=xppfF<ci0lvFAklHHoZsV6N2w%%!XSvok~h+J9Jk(z9GBlY---;#mT`4DEG*+v`(
z92yCN3AasUG7r5$rR^OrF7PUzF&u=O_8LUo&vakK8}SHmM(%wM0|t}L^>bBN1-aPK
zgf!h+fJPx_qBepiwR@1fCGuf4)(j`S2DUjOyv_8ypL%eE{)mmsfc^q_Q!o(=`LIS=
zdM)1=?9;w<P+=ugQzO1(d@tsrx@YA&6-_S-a@)J0F)0Nua~O2h+(u+!p8?sL50i@V
z()RW9#e$@u{gg<F^#Q(KEN<e!&pC=e0RoSj&UI6Q`&oEZw}`PWk7lS77JO5!C7Si9
zd;g2G2!IwW{nO~t&vgxdVo%~%p(Le3mQNSZD7vfF<?}sy(ZnJH<8)3^d20H3eI!ra
zu_-ysl1dt0P&jkn8J4Yv@<`I`RwSY9ME4%=Qj5pT_j86w)B&q#^G3y5!>h(j4xP6M
zB>CBI(c0^;`?iUkn}rKEhK_X}BW=tCV)w->EKt-7qAI#e9cao%o)g28I|MxanmEG`
zeDirjDOixJR+IGaVTo}-JvB{~P0xX`ubtnh*bK(&n0dU8ma<3<?M1hSS5&;^l6)l`
zIhprtQVX)?&`48xIF7|XnzBUhtVq!kB<hlmMJ*HL_P4cqEo}0s3J=<Afpt7O-<RSM
z%KP(u=)4FD9Iu8ZKku*x259a`=b)A|%t)<!n@D^gL8uJnsF{wUDCTh2z3I%#o1RN?
zPp`&;Z%@zy4{O?}g<|e(b$I-3Pe$hIv8-}7F1@(is3r$HnzqokokL(j#^#^NR0N-x
zhIW+)5>U#ACqsqE{bU18T)e(!pToxU-r;+eqi>YaS^)VByUYsE)cQnmoCwHQpHraP
z;zmQYGZe9BZ@aewLHl>AtX+lg%}b^yhC9?^La^)nRs5M8B9y{QdIM2B=3PUEevs)>
zv^7lB!c?Q2o~x(G*dODlP?sD;FagDtQxh#)h+p5HL0P_4#<;c+9S#ZdhO?kD2MT^3
zvbV7WsP}2V2`fFz1ZA0mv&f@JPnb47M;R^<9(`PX<|cX|n)i=z{zSJrxhPdjzAAi2
zsgEZ5%P2zI1&P8+8fj}Sp4v^qmmf{i|J;^%@DIC=kB>RF@P!tP-F2*pyJgnXSetlB
zVKEToK9fR|(OIBx<pzGDmHsyKxO?zp^r0|t8a_vgheFsYl2cUe8`*}ddQHLM!a?GE
zDy5B(9{nJPcCm{w=(3o<irxoV&sbLf*8PDeWaZ22(VLE)DdOx_0{yC8xvb{OQF@@f
z!XlYfup0YSV+`$jY*#pbYktEG7`+$ZMD$}QxKP97%ZAy=7Z;qk%8z-4&vEhHqaQl)
zO4{HV2bQaoTnjCOv8>Db0<JFwnbyyi2&(TQw|*P|TQoq;zn&x9z5%zv=zO*2>t%rI
zAkJvRFua(MZFC%x9n88rBPIQenzLp{87fTiGJn_CO?-@AR;|RX+gU<Kh<o5fm~&%~
zbA>i3z$7=@pH10xoF4!4)rHcJB@l^pSSU87rHXh?5C_XUWf_@r3AUG?fAJ!_tv~2}
z#6c0DeCa5yN|I5^E^QIC#^bv{?dSW_oTXvK1F`EJDYWB?PMAp+P6T*wP?yRba`06F
zrQMPuQYq4BbF?uxkmh|r=hH1}G@5HWIuvD5v7n`nH!M*kGweEl<0kf1W$Spv`G;+H
z4e+O+C~+hF`D;G;ylDA6GX)+$4$98-LW=lCFEF{LWXf$SRc5c|;=(@3x&D-8FikQJ
z4BSF|tN8M?$S0`GYHottzP&rYjMg%5^k>VQfpunj4m=69jx5W({OOkin75uJs^CTX
zTT0MiTt~t&{rUZ~SXS9KK?>)(AhnTxlX<}x6{m**?&j-$W0V*4jDKzlc94!}AOw5?
zId=ZBKI{wQlyz~sJ<2O;U+5`=3!2_5{<_oyg5DyemYFM2VFHJ2`HjL-$b*{HvG13M
zi4V(+Gx1cmf_7?#a~nXUdZL`*`%9h8FI6+>qEpyHee=_F6U#3pnG`9!SHfHq|Im`X
z%C=&$J(9~~Zg=n(CTevZulk*CY|4?^b+eU3onFqWc6V|*ofNAGMP-Y7@7vT`qm<;x
z`amg9d~{!bv2{EoNDK@0`|xvD_FxrBca1sM#Dvgy_=}Yq7%na&+{lkMP<5zia2|!d
zlrO}D<e3p=)MUV31Pfhj;>TpvV6(;B)YKa^BnkfV=M*-59E?2L!+p8*2hUGglfvvJ
zwJ#ndc&KfNMy5f09b)pQAGJLIx<hViv3T1}6PeN@?DSFG4;5uw(UY+~J-7|dSQ#tJ
z=m=K`;>%Cjo&NlNGj)3R>V=?>mT&!6CCUpUoMnf!{=T8Y>$Ah@3&P$N0%F$jLcutE
zifgP}u>>_Gn|uBv&xHNRXa^Gd@Ffe{-28*IrXCiXU;3$|L>G(GCp0UyAs0m{S3*{F
zli!w#8J#iQH!-eC91T*gMm!6A4-o`xOKt>WX;z~W{H{MzRz*BM+xS@yIE5p&NNEJ-
zigI}(-X73mJ91Io1ksT%X%5IUpIwyA0SKCGk{Zb0h%T*AFcLl+D9Z971O670JWNkd
z@9zig-^bm`)zQq?#>~#y#M9l(!okGV%FF@44He<#=H}ytX~^;XT}1MC)AN%Qz#ZTT
zumgDfebWJ?{?5Y`VZ46_qW`pEe_NgaM}XD;Z~ng!#{VhgUmk#y2g?07g`1nsQu^<r
z|8qUxYYhIkO^VLeE`KNS07#U4fP=Sn03a#`76^}!n2eH|h91nq#t!A?6BH2@mz0rv
zt)!~1rLC)PWMXDvZRg<Z=Hcbz9~cx84v&sYNJ>f1%+4(+F0H7lt!r#)YwzkE7#bd%
zoSs`;THV;*`F3#h<M-Lc)y@6W-#if&DOEW>sECL=QpvwFK^Xu5Vo5Mi@~=$t-#L6b
zILiMu{+IfX2N^!eFhU;|5UkK_20*|MktDdRs62hG%o&v>o}YOcpC@8|Ru{$7&y8cm
zQGd8je!fL*x>tW>HhE6G)?wgp7@~4j*<G<($l$+_lvK_9kSXY1x05VRmrri)9rqhW
zf=N_3oHWnnd-fdx{Kw)&%&Q=r;&b+y*dr16^I|q#!tL}{xjOv|m}BrzX&DB6DzO2f
zG=7fZW8Lm{8^)L?Q_oE79YGTSUk;M~WN2X<<b<TDhYl*z(@=kz*K!0D>O-CGr@?))
z-3Ns{-)jvL0C3?ym}E2jq<k7J`$BPS<Bh3C|IiT=6XJ6#Xy}NYd#mVO%y2XCo<<O{
zct#GHN;l!LxIcB|;sOb-{)lhj^!6^eN@5V2_ubqg0hmAV(=xN9qi>H;5q0C`u|9Nc
zzl%Um#V&dm0!FS#`$$PTvZ+Wxk;OR9&&R+4Psz2y`|Y3EmTP23<5o7NhFeLwz<8g?
zlzV28<Uz}pb?y?yRT?8I|3!PBDNWu#chW;J`RD}8ectP5`UT_FdNUlq3(NagVDsk`
zS%fCU<R1t%2-_!}uPnncSP!4s^D;^=`?cFzSSD-PFAWMke3@PYX>inONC{Ob@v&)&
zXe-r|YMINT1fwV`u*TFhg<M~Hk-&W6rk&Pyp+=`mZl=VDf>?Wa2{oSmw|2*i<)xvX
ze7lxw{uIk3B;S?#B3%W)H6FlJD%2{7D4caguEJi7Z_b@>Lr%ba6~z>x6yIW<j%zXW
zMv8>2xHP0nW?~LESJtEuff13`{M)zKFnQie;97ID?PsOhDztc_9AH_j*b%xQH5mNe
zZ5|Ty4}=wjE#|@%S!aV31F~{$!4Zkvmy;b|W>yJQw+!XEFFH+E!yZF;RUAo}C26*C
zw|HU8Y4CB`*0swIk&AWq?ij*keF`F)7&;Un$56`sM56|TL>0HRS7)yP01#x!5k{p6
zfYT(AZFGwZa!`=qs-|lRFZ^Mhq}_iV<jQc{V)pgqgPWPqcQP!uuIQ~2vhDGBo72lG
z7uw_-`<}ja!*5qpwNp23+7i6!LUta>_J6D#v<OU|#pK)#ooCmh0adIkgcG)!VQU^W
ziQE4H0dNqJT#?0gQZ5Nhm)AJL)RMABANlD3NO{_m1Xj=Z)rbk{;Alho)bqaV0^r`)
zq0B3sIZycM+5i@fV|-Wz!|Xed=rt{bKLQeiKIhA+tT0B*<AbkRVQ4MSno6fwy5Fi)
z%tQ!4hG&NC(-EskV}1dB;^D@O)GDQ<H+%!y9YhBn;-kI;-o07fJ>S!yXu&nTL4t6r
z(kCZqCjeu>`lv}(5V~2NwFLSI%KO47=hFM2rWF5A7<`WqLBno$`6w_j!GR0zspb3+
zgdU{Kp~_QMJQ8df!_0jF8mR%FBv}@UDgZFQ%p0PDlrRw-ZI3T+4EFPR2w3_W72Ojt
zQUwP>3ZqIU$sAzAePBFq75=Addo8v1u;aC?3<2rA5ra?{jm*At)zaHfIZ#z|UMA3G
zWq@z?FI;LhLzprS9gN2ARRF`Tjz&f$#RIt`5Xuck7t@9!rxN4I%1u+iGV}dngu$Lp
zWorx_#3sKtP(RIm)RdoSb_f2{7;|KZrrhjKlG6kuWLTIES(s(IiV?O(r>HEl|3EkZ
zY=qNa&@hrY)&c)zhA9EQ_yB09m#A}ERgO{QmC3sUB}?^bbyOO-$(w%jPcOTaiGf<i
zDRJ*D8tnAHlj5ErlUUa$2xAe|(k>rb)T-jeRJ=;AN*boBD3oNb7<&<t=7X>FMs&4T
zl@J+AHhRN}%0T`ZZ@;PYs4%rcPHOQ5DIS6wBgBT(3DzlkX68+7kVavi0^`m~qFc3D
z-8;6q=wB*bpT@jQz%6BhtU4wJ^dhmSi@rv}TFA$X1n;4QR*^YLUqOuk!x#TRctKd@
zd4KPaS>NjzYtO&GTzF`)v>U?v8a>^m=DXHuVW#nJHA|?xO-g19r9cY1rp*hPcdvfh
zR#6-lptKJ+!{jWTBs=`F*X=HoAhQ7MbKY|7um~Xe;8BA?_P2|Y;hTaD4LUAu)FmMl
zH^T>1`5B5jN(Lj>R8x<c3Sfb_U};MF#@4h}m4_UW?r$x$w#5nw`ZrCamx~Yzj;KCv
zfPyJC8Wo?hfOLos8w1?{R)<L5Yu3{U2H&Je!hs;KY8GNlkx6@${xOXVlz$+KAk0e{
zp0Eu2U~vR<Q(rV4DoA?j?fS%?9m(9tkaGehD|=1Sy9qq{Cx>o@>OA9z2Kg~?(2x%l
zBUH-vhtDckrQ@SNcO$mrh9;GgEB=n6I!f{M=V;{<F2`=uer}LLLw(V>u&A7~SM94B
ze$L~J`GiqA`^`Uhuj0t;8Uw4nhO`ucLTcgt0=VuXD#ZfH*kA-s6j|yt{~XWCgp8`F
z?+IRrpQsu0My3h{RKppTSwkv?E)Yh|3fyQ;u4jLv7iVx%d;gL;P(~*5ABYuzrC}pb
zmSKk^6JhN-7^P6;9hQ^y1LwHBi6{ZA{Xmzk*~lNP1q9R0;-iFS0$VwnROZpsaKceB
z2nqSQEL02ka4f#mP=j${8HO^Y$E3I-(g{ALc{&pxchYz=b2F-TlOVcI{G+;BA)cKS
z^0#|7?QD1p6Cm0#)O4)AS~GEG+w*e9Huj><LQz%?nDo|^q3Fc$Q_)UQI~rs@&b%<L
zbUg#6%<%0~VGacsk3W|a4P>|?-cHb|d|e?ZxYz_SqR@ZZ`}Nhxk<vd9KLAUmgeNjq
ztxpAB>UkNP@AGqO!JZs5+QyD8me>?W531c;1q#Lr#>0Wk_U2eg%lEYin_d?SsJq;;
zG(XRud9@_kil!yx>51wY8DzfU^h#WwK=KpS*RV4CtgV4j3y%Wc(GAWUzfqt<huMoX
zkBqU?xH)ZrbGm}gsqiOWMAax!`<>{8O`M7n=^fE>j9kJVPddD8Z?Q1=)NZJC=F$b{
zb(VSaqZl*-x$tS2am(tD*K1$BH_Jdh6|SEY=<ZE9m&M~`m7-eB{0EW%V7Y$ai!8R1
zg2E46`#`;DT3yGEQf8_ZI3fwY4ifSb+hpz8&U47W+3jZpoSLOmv^kF)R3{-A)e@_i
z4FqN=#A$kLS7z*#O0s6PF=%lXLIdw5(yb3t&s;nPEtw4Jn-qX>!5@(ou4TI|bB|M1
zwvF$gdrb9>JKl9?%vj0duXb^no0|ofMlEcMk<gF|R8|_mQP_iF`MvwL!>HYvTsoK<
z5j(2E9oe6I>qufj!K8?tH9|o)JDp+;Qu{4oi%FFs?3a(*&)4JsK&k+&FbA&4zjufO
z&fGMB%4)vJuzsM;Z)@WvD?F=!NC#RR!d6bHq77N_LNs=V(KyV<UsxXr_-2aY^rhhg
zh_E6N1#+WuW?j{W849y@jbHGJJZfA5w!0^LT(($p#H7QTfLGJP88w{i)h*p0HGy<9
zbyVchC~izVF%fO}hA3L)+U+xPRy1_X*fAOCh%-QWLrd2*Ru-vPAAJX!S}xBdluw+v
z0RAd!^XWN$-TEASk}Fw++IF!h;%?FtVFU+qi_4kY9)e=S{(%euSdOm+4#@5M6eCJq
z2R{NBG*)a)1wmkxsF|;UF_b|s&HE!HP1ho@`@Hcn1*9)=wH9{^TN6!vZ51`u`Y2)J
zx%X2XrIv4(4k-MfMYZ8v%l6u-A9v}J1ZTm>bf!!oJ6U&Doi`FJ>2bj_^~5jrf>Da(
z49QRQA?fXMtd-F~`&YECt0|$qNK^6o2aA~e<row9U~S1%Y)mJmKSEDE_a;485GGmO
z2w7+)jB3zyg(7X3u=i(IaviK23w<nRn7h=;wG3Haz!3Ex$QpoUE5Z{2w(WZzYuz~r
zT2c7!uRT>wAheQ@a#Xl-?^5-{Or2poD)ZPZvrBmi!Lezl8$BMQh$Vux{%Zw#tg<YS
zdBRYWLbt_P1|tzGm&2TAtsoQ2H+5=dOj2W{ObfrxW)QC!)yNkbu`VCOl8X~Qj(pny
zO>(D<q(3Pc+W7U!@WXRyd86~2H$J%~-0&PckhYqBlidh{4p1Z#wHq5)fxUo!Y^696
zKw<rrH4T%WwJ<yHd;8v4z+w~4sacZAK<sO#SE)E58rlCqZUC%}8on<$8o`R71J}zq
za{0JvTg5%x>X7AK%qC5*PkTwhBw6^yUAUH-M=!g5J7|?Q+zc&h1r-5C%0O#*)2}ym
zDdi%P;N*xYdctoIaDB#kz}#hd51M?R7Hc?_qMTHTnJ-9mG7Fn+kwb?k6|c*=uKg_|
zM?iv*OnOE?`v&)g1D^ZUR6Yuu9edT1X(4ShlQ<K+8V>l%FDmhZK#vO8xJwz%xW<@z
zSBbjLZUkp4dBeT+i2)x!5(!f&Y?;A;=XJELFsLm!=^w}sfUOY9Q<mW*6@tHi*+&_K
zpue~L+?X96Tf?el=+<12>{k3#3f}#s)81(QeYxz-(#C2DaSuI3wJsn2dq$X2sBeIh
zny_^FuI(AlqTGve!SQ5BZ`B4R9$gjEQlVF9sIuP-lGwV|%o?`D0)t1TA7LwV$lh{U
zv+i1E!PUHT)vV>J6wqHZ8(a&TG)wY??E54X04{@838X{BaP`oP`QS*kijjSnq%@e|
zd=XB)Z=-szn3R+fg{8h~G|2O3#2Ob2(tPfFneY4kKcFD24GXRa6n7~T3~RT@V!Dkg
z1|6n&<?5CObz{Qd1(~-^HHlKN?6g7H7(5ulu1uID;tj)&N?EJc{KV0eghBOZG|bJu
zsJmHJKA4jiI#wo^NWy$J&43SJfYuKvQw6lujg&WYln6E@gS5C_nO|`kwo4cc7e9v7
zI^uF9@fz|4przP0T3R%yhY*w$MywfEY;8yEdc@lH>GG5?2i>d8>P9hSnO)togfaO(
z&=$<h+weJwh5(<qV!YW<HW6r(<K`X$7M8)#m$OwQqc<FnZ@q8_yce!NI(a=r97h@-
zKMvf7!rZX`Fc;$XG$REEhG&TpLk>O{9jL~7WBln>Rs&%>7Z}e47M2T6{d9q0P*lF#
zAIje0!TF|C{A>t8*3_*48d~6<ldrdS^fC+@ehe{h9k(+S+7mMst<~vL-?kxQ9@ZTo
z?J(|%_6>_}zStv1D(b<!Vk2&2+Tu*c!dYPZW^BYzu`*X-8;YSiU>dxnL@%0Zc7AIk
zv>O47sL#%JbY?ZbYMIyJ9JRGLI<oiT^X40JX@K0F_F5_`^dgd9pFLwM(lQ<~ayo>`
zd~dO6&t;Q(1Kt%vR*RU#lw4xI*FBnO-pd;G1*QLLFcalf^1aDfZE~wO;lD3Uxuz_V
ziS2D*Howrh+9Y=6(>V~k5wki)jO8Sf5_WhoBPfI}hkS499Yj31p<h6C0i+Lmkf}~C
z3<+sDp-SpZ2L^Y2`RTj1tkkIraaW;~Bnh}o<zc%zF76d!MP`Hn1@`mz*`X4~hvE6k
z&Vl_0yQN;_+3xv@;sr3}6feQfsbt;-djUT;VUS}WmcA5m9ga|sX1vCZ+igeYctu~^
zTkckWlxgT0KcHBEOPtfO&>n(UU2a|JZ1Z!&4J*v~YtJM^NFcZ0C9b}R=TezNjXCik
z@SD)*^v(-M77SYjh0pNGF8N2`%M__~<C=;nNy~iCczb3Wy&e3tjU3up)>sO0_llL?
zR|{q;Xl+!|q<in#cOREBua#Pj6oUzwtBIDLsWV!PB1LU9fh)6Yn&T<HuABM5#6oUH
z6#C9~g9Jqvd`D2intsFktmeFeeY`GnW^v8_tP_<Ti;Bz9yBJ$iXvRFz(uD0Oqt>|G
z-MW&{>aS<Oi1-ZdYdekSwWRTVeCaEc{DI!62r=@2MqMttuqn|OAAym`jG-$;UJ_>*
z3EcLCZ!>>}G+C`z#KY~CEYikZiQ7JWXZr|vRyA3#b$U=d+BcFuR;k`*m0Ao+j5AAa
z6a>3Da~+NZ4tr<u>Sen@rpk-~aCEU3{7A*?uR-$tjS~KL>d`?sIOl#k>^(QpNTqtK
zqia8wAtJ@+bThv_ynOF81j*|$T}p}Lmg4?I@XlKF#w#UFy3oW%&?9LVBT|itU4Agg
zt7rTo`*IiFU=N^pa2kuTdHqW)6y-%1VnCvK<@5EqVYI&xB%l3>qCWr5B$m7wzPwsP
z>&4l3#QwNb$9tCbI3*(JzG=^A)xW|%6~VXbBJ7PdvanxGYi`IOD8eklXMXU$xb5Jp
zv^X3eu1sPE8B@cnEQ`rYj(V7*xPo0IPozb9l&kVqk&xgA3*?-=QJIr^?}blSEsnGf
zewI{y&T2-$Io<T;iU{%y&sMA(_+rwywm`L>hrdkvtMxOM^w#IXw~7p|Yfp9><(J59
zM&Oz_1klEaGOFFlGtdu-uHGN|{7D^s0npazB?080NgvUjnlmp3SxO|wIbNr*awz2r
zsvfudEv`1w?+)S~9lx?!<t-WO+EmrcDNo!8TdJ-3MI?DJ^XdA@pDX_L@utYhcSc~G
z2_lm-T)blwD$NH4xTJT}vU|yw?H`{=-e)Lm^f%EYT^$a6fB2bbbbh>qdtYczQXzl{
z2)bTl-_Gu6AShOX)D^z)bVm<7eu=Vyam>Q3iM_=Vh*dV6r)#~2my-<<=DY>fN~5N;
z5UrBMx|BV`elqvNRg%jiR<Ow|`w;7=>ji4KU3dIDHFzcV?j$|kY1FPUZJ|d6no7e{
zPF<qj&W;|#ZNOg3Ag3q`Ns9!WyF5B_B;WN_v%}eFq}%qzq!&&4oN#cP9ewPtThWOG
z{}C0&axFwd%d6hg-lCj8=Us|JPmJqc4o^cKtn9@)mQYvi=HCfy-J(^pPJHcxdC%7;
zmdEF2X&RX!sUa`MZ!bItMsRTfCLt^lWr41W<0Scnv4tw&&TAGJB+la?Yy{TQFoTs{
zmoZWXl)jRkJ@#VL5z;Z{p8uLf-~P>Y_yDCJ^2dA7!#Uw@Ocn~JEh>V$<?V2md`&)z
zDJ5+t2^YNGxFb16jx!(xRwBjP$>Z?o$ezX{OPm(B#C<JgDG!+oP$wcA{6;gr6V2hy
zE+QVZE^Gd_+d}}>#<g)}6k<sF1&2#joI}+2n%PW@LV-DFZJ7{{h3!WLh3pW>3O|2&
zl{Rc-4vOzln-=+$CU+j8ahr=3b>%l)1Z)jP@8`p%qkBL%QD%MJNcjQN?__x`vOXU3
z$h5SXsja3;;*<Qj<E+m9i?wK!F;VK8A*H79zRcAYe?LXH$qT04+{QWF=bJgP<4JPz
ztUZq*e2zR@=li}-_g>3mC!_|2%BQ*f>B9}IoOW-!kk3O|fAcN2?UaSJ{Ry))Zt_g5
zpZ<xh@!+}bt3u%Atk>>|psR{CWWUza;7{Wcf-%^U+`M48NiBLDBHLVTW>9zP0C@=~
z-?z3Ptt_-CGr1ll98M$}uNT~<8f_ms=Z5O{N6Mz!e?5HW@TT(Z+X(j2UcyU!4w9fO
z1%)k}O1C~=DD^lM42@3!0#%VC(V*YrGgrCq1nmo^ik``du?n<8{a$u7KMJgC;J+*9
YdjCZ_?Wr7v#yEfT4BEkpaZzjfUmgnumH+?%

literal 0
HcmV?d00001

diff --git a/tests/test_mpeg.cpp b/tests/test_mpeg.cpp
index c1179ee5..5a990580 100644
--- a/tests/test_mpeg.cpp
+++ b/tests/test_mpeg.cpp
@@ -64,6 +64,7 @@ class TestMPEG : public CppUnit::TestFixture
   CPPUNIT_TEST(testEmptyID3v2);
   CPPUNIT_TEST(testEmptyID3v1);
   CPPUNIT_TEST(testEmptyAPE);
+  CPPUNIT_TEST(testIgnoreGarbage);
   CPPUNIT_TEST_SUITE_END();
 
 public:
@@ -119,13 +120,8 @@ public:
     CPPUNIT_ASSERT_EQUAL(44100, f.audioProperties()->sampleRate());
     CPPUNIT_ASSERT(!f.audioProperties()->xingHeader());
 
-    long last = f.lastFrameOffset();
-    MPEG::Header lastHeader(&f, last, false);
-
-    while(!lastHeader.isValid()) {
-      last = f.previousFrameOffset(last);
-      lastHeader = MPEG::Header(&f, last, false);
-    }
+    const long last = f.lastFrameOffset();
+    const MPEG::Header lastHeader(&f, last, false);
 
     CPPUNIT_ASSERT_EQUAL(28213L, last);
     CPPUNIT_ASSERT_EQUAL(209, lastHeader.frameLength());
@@ -163,7 +159,7 @@ public:
     CPPUNIT_ASSERT(f.audioProperties());
     CPPUNIT_ASSERT_EQUAL(0, f.audioProperties()->length());
     CPPUNIT_ASSERT_EQUAL(0, f.audioProperties()->lengthInSeconds());
-    CPPUNIT_ASSERT_EQUAL(176, f.audioProperties()->lengthInMilliseconds());
+    CPPUNIT_ASSERT_EQUAL(183, f.audioProperties()->lengthInMilliseconds());
     CPPUNIT_ASSERT_EQUAL(320, f.audioProperties()->bitrate());
     CPPUNIT_ASSERT_EQUAL(2, f.audioProperties()->channels());
     CPPUNIT_ASSERT_EQUAL(44100, f.audioProperties()->sampleRate());
@@ -421,6 +417,27 @@ public:
     }
   }
 
+  void testIgnoreGarbage()
+  {
+    const ScopedFileCopy copy("garbage", ".mp3");
+    {
+      MPEG::File f(copy.fileName().c_str());
+      CPPUNIT_ASSERT(f.isValid());
+      CPPUNIT_ASSERT(f.hasID3v2Tag());
+      CPPUNIT_ASSERT_EQUAL(2255L, f.firstFrameOffset());
+      CPPUNIT_ASSERT_EQUAL(6015L, f.lastFrameOffset());
+      CPPUNIT_ASSERT_EQUAL(String("Title A"), f.ID3v2Tag()->title());
+      f.ID3v2Tag()->setTitle("Title B");
+      f.save();
+    }
+    {
+      MPEG::File f(copy.fileName().c_str());
+      CPPUNIT_ASSERT(f.isValid());
+      CPPUNIT_ASSERT(f.hasID3v2Tag());
+      CPPUNIT_ASSERT_EQUAL(String("Title B"), f.ID3v2Tag()->title());
+    }
+  }
+
 };
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestMPEG);
-- 
2.40.0