#!/bin/sh

test_description='common tail optimization'

. ./test-lib.sh

z=zzzzzzzz ;# 8
z="$z$z$z$z$z$z$z$z" ;# 64
z="$z$z$z$z$z$z$z$z" ;# 512
z="$z$z$z$z" ;# 2048
z2047=$(expr "$z" : '.\(.*\)') ; #2047

x=zzzzzzzzzz                    ;# 10
y="$x$x$x$x$x$x$x$x$x$x"        ;# 100
z="$y$y$y$y$y$y$y$y$y$y"        ;# 1000
z1000=$z
z100=$y
z10=$x

zs() {
        count="$1"
        while test "$count" -ge 1000
        do
                count=$(($count - 1000))
                printf "%s" $z1000
        done
        while test "$count" -ge 100
        do
                count=$(($count - 100))
                printf "%s" $z100
        done
        while test "$count" -ge 10
        do
                count=$(($count - 10))
                printf "%s" $z10
        done
        while test "$count" -ge 1
        do
                count=$(($count - 1))
                printf "z"
        done
}

zc () {
        sed -e "/^index/d" \
                -e "s/$z1000/Q/g" \
                -e "s/QQQQQQQQQ/Z9000/g" \
                -e "s/QQQQQQQQ/Z8000/g" \
                -e "s/QQQQQQQ/Z7000/g" \
                -e "s/QQQQQQ/Z6000/g" \
                -e "s/QQQQQ/Z5000/g" \
                -e "s/QQQQ/Z4000/g" \
                -e "s/QQQ/Z3000/g" \
                -e "s/QQ/Z2000/g" \
                -e "s/Q/Z1000/g" \
                -e "s/$z100/Q/g" \
                -e "s/QQQQQQQQQ/Z900/g" \
                -e "s/QQQQQQQQ/Z800/g" \
                -e "s/QQQQQQQ/Z700/g" \
                -e "s/QQQQQQ/Z600/g" \
                -e "s/QQQQQ/Z500/g" \
                -e "s/QQQQ/Z400/g" \
                -e "s/QQQ/Z300/g" \
                -e "s/QQ/Z200/g" \
                -e "s/Q/Z100/g" \
                -e "s/000Z//g" \
                -e "s/$z10/Q/g" \
                -e "s/QQQQQQQQQ/Z90/g" \
                -e "s/QQQQQQQQ/Z80/g" \
                -e "s/QQQQQQQ/Z70/g" \
                -e "s/QQQQQQ/Z60/g" \
                -e "s/QQQQQ/Z50/g" \
                -e "s/QQQQ/Z40/g" \
                -e "s/QQQ/Z30/g" \
                -e "s/QQ/Z20/g" \
                -e "s/Q/Z10/g" \
                -e "s/00Z//g" \
                -e "s/z/Q/g" \
                -e "s/QQQQQQQQQ/Z9/g" \
                -e "s/QQQQQQQQ/Z8/g" \
                -e "s/QQQQQQQ/Z7/g" \
                -e "s/QQQQQQ/Z6/g" \
                -e "s/QQQQQ/Z5/g" \
                -e "s/QQQQ/Z4/g" \
                -e "s/QQQ/Z3/g" \
                -e "s/QQ/Z2/g" \
                -e "s/Q/Z1/g" \
                -e "s/0Z//g" \
        ;
}

expect_pattern () {
        cnt="$1"
        cat <<EOF
diff --git a/file-a$cnt b/file-a$cnt
--- a/file-a$cnt
+++ b/file-a$cnt
@@ -1 +1 @@
-Z${cnt}a
+Z${cnt}A
diff --git a/file-b$cnt b/file-b$cnt
--- a/file-b$cnt
+++ b/file-b$cnt
@@ -1 +1 @@
-b
+B
diff --git a/file-c$cnt b/file-c$cnt
--- a/file-c$cnt
+++ b/file-c$cnt
@@ -1 +1 @@
-cZ$cnt
\ No newline at end of file
+CZ$cnt
\ No newline at end of file
diff --git a/file-d$cnt b/file-d$cnt
--- a/file-d$cnt
+++ b/file-d$cnt
@@ -1 +1 @@
-d
+D
EOF
}

sample='1023 1024 1025 2047 4095'

test_expect_success setup '

        for n in $sample
        do
                ( zs $n ; echo a ) >file-a$n &&
                ( echo b; zs $n; echo ) >file-b$n &&
                ( printf c; zs $n ) >file-c$n &&
                ( echo d; zs $n ) >file-d$n &&

                git add file-a$n file-b$n file-c$n file-d$n &&

                ( zs $n ; echo A ) >file-a$n &&
                ( echo B; zs $n; echo ) >file-b$n &&
                ( printf C; zs $n ) >file-c$n &&
                ( echo D; zs $n ) >file-d$n &&

                expect_pattern $n || break

        done >expect
'

test_expect_success 'diff -U0' '

        for n in $sample
        do
                git diff -U0 file-?$n
        done | zc >actual &&
        diff -u expect actual

'

test_done