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-rw-r--r--t/lib-pack.sh98
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diff --git a/t/lib-pack.sh b/t/lib-pack.sh
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+++ b/t/lib-pack.sh
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+# Support routines for hand-crafting weird or malicious packs.
+#
+# You can make a complete pack like:
+#
+# pack_header 2 >foo.pack &&
+# pack_obj e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 >>foo.pack &&
+# pack_obj e68fe8129b546b101aee9510c5328e7f21ca1d18 >>foo.pack &&
+# pack_trailer foo.pack
+
+# Print the big-endian 4-byte octal representation of $1
+uint32_octal () {
+ n=$1
+ printf '\\%o' $(($n / 16777216)); n=$((n % 16777216))
+ printf '\\%o' $(($n / 65536)); n=$((n % 65536))
+ printf '\\%o' $(($n / 256)); n=$((n % 256))
+ printf '\\%o' $(($n ));
+}
+
+# Print the big-endian 4-byte binary representation of $1
+uint32_binary () {
+ printf "$(uint32_octal "$1")"
+}
+
+# Print a pack header, version 2, for a pack with $1 objects
+pack_header () {
+ printf 'PACK' &&
+ printf '\0\0\0\2' &&
+ uint32_binary "$1"
+}
+
+# Print the pack data for object $1, as a delta against object $2 (or as a full
+# object if $2 is missing or empty). The output is suitable for including
+# directly in the packfile, and represents the entirety of the object entry.
+# Doing this on the fly (especially picking your deltas) is quite tricky, so we
+# have hardcoded some well-known objects. See the case statements below for the
+# complete list.
+pack_obj () {
+ case "$1" in
+ # empty blob
+ e69de29bb2d1d6434b8b29ae775ad8c2e48c5391)
+ case "$2" in
+ '')
+ printf '\060\170\234\003\0\0\0\0\1'
+ return
+ ;;
+ esac
+ ;;
+
+ # blob containing "\7\76"
+ e68fe8129b546b101aee9510c5328e7f21ca1d18)
+ case "$2" in
+ '')
+ printf '\062\170\234\143\267\3\0\0\116\0\106'
+ return
+ ;;
+ 01d7713666f4de822776c7622c10f1b07de280dc)
+ printf '\165\1\327\161\66\146\364\336\202\47\166' &&
+ printf '\307\142\54\20\361\260\175\342\200\334\170' &&
+ printf '\234\143\142\142\142\267\003\0\0\151\0\114'
+ return
+ ;;
+ esac
+ ;;
+
+ # blob containing "\7\0"
+ 01d7713666f4de822776c7622c10f1b07de280dc)
+ case "$2" in
+ '')
+ printf '\062\170\234\143\147\0\0\0\20\0\10'
+ return
+ ;;
+ e68fe8129b546b101aee9510c5328e7f21ca1d18)
+ printf '\165\346\217\350\22\233\124\153\20\32\356' &&
+ printf '\225\20\305\62\216\177\41\312\35\30\170\234' &&
+ printf '\143\142\142\142\147\0\0\0\53\0\16'
+ return
+ ;;
+ esac
+ ;;
+ esac
+
+ echo >&2 "BUG: don't know how to print $1${2:+ (from $2)}"
+ return 1
+}
+
+# Compute and append pack trailer to "$1"
+pack_trailer () {
+ test-sha1 -b <"$1" >trailer.tmp &&
+ cat trailer.tmp >>"$1" &&
+ rm -f trailer.tmp
+}
+
+# Remove any existing packs to make sure that
+# whatever we index next will be the pack that we
+# actually use.
+clear_packs () {
+ rm -f .git/objects/pack/*
+}