bzip2: rewrite bit of code which depends on integer overflow

function                                             old     new   delta
sendMTFValues                                       2093    2070     -23

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/archival/libarchive/bz/compress.c b/archival/libarchive/bz/compress.c
index 377f2f1663161d89b99ddacce35c3a0a6bc142af..271982cf2eb16b3954c467814458c25e7f5baaac 100644 (file)
--- a/archival/libarchive/bz/compress.c
+++ b/archival/libarchive/bz/compress.c
@@ -297,7 +297,7 @@ void sendMTFValues(EState* s)
        // 200..599 = 3
        // 600..1199 = 4
        // 1200..2399 = 5
-       // else 6
+       // 2400..99999 = 6
        nGroups = 2;
        nGroups += (s->nMTF >= 200);
        nGroups += (s->nMTF >= 600);
@@ -317,12 +317,12 @@ void sendMTFValues(EState* s)
                        unsigned tFreq, aFreq;
 
                        tFreq = remF / nPart;
-                       ge = gs - 1; //underflows on 1st iteration
+                       ge = gs;
                        aFreq = 0;
-                       while (aFreq < tFreq && (int)ge < (int)alphaSize-1) {
-                               ge++;
-                               aFreq += s->mtfFreq[ge];
+                       while (aFreq < tFreq && ge < alphaSize) {
+                               aFreq += s->mtfFreq[ge++];
                        }
+                       ge--;
 
                        if (ge > gs
                         && nPart != nGroups && nPart != 1