t5300: avoid false failures.

Junio C Hamano · Junio C Hamano · commit c97451ce0985 · 2005-12-26T18:23:41.000-08:00
Johannes found that the test has 1/256 chance of falsely
producing an uncorrupted idx file, causing the check to detect
corruption fail.  Now we have 1/2^160 chance of false failure
;-).

Signed-off-by: Junio C Hamano &lt;junkio@cox.net&gt;
diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
@@ -142,29 +142,35 @@ test_expect_success \
      else :;
      fi &&
 
+     : PACK_SIGNATURE &&
      cp test-1-${packname_1}.pack test-3.pack &&
      dd if=/dev/zero of=test-3.pack count=1 bs=1 conv=notrunc seek=2 &&
      if git-verify-pack test-3.idx
      then false
      else :;
      fi &&
 
+     : PACK_VERSION &&
      cp test-1-${packname_1}.pack test-3.pack &&
      dd if=/dev/zero of=test-3.pack count=1 bs=1 conv=notrunc seek=7 &&
      if git-verify-pack test-3.idx
      then false
      else :;
      fi &&
 
+     : TYPE/SIZE byte of the first packed object data &&
      cp test-1-${packname_1}.pack test-3.pack &&
      dd if=/dev/zero of=test-3.pack count=1 bs=1 conv=notrunc seek=12 &&
      if git-verify-pack test-3.idx
      then false
      else :;
      fi &&
 
+     : sum of the index file itself &&
+     l=`wc -c <test-3.idx` &&
+     l=`expr "$l" - 20` &&
      cp test-1-${packname_1}.pack test-3.pack &&
-     dd if=/dev/zero of=test-3.idx count=1 bs=1 conv=notrunc seek=1200 &&
+     dd if=/dev/zero of=test-3.idx count=20 bs=1 conv=notrunc seek=$l &&
      if git-verify-pack test-3.pack
      then false
      else :;
