From f3277b333159976a0fceaaa052f545d55d252b9a Mon Sep 17 00:00:00 2001
From: Ole Tange <ole@tange.dk>
Date: Sat, 14 Nov 2020 01:10:13 +0100
Subject: [PATCH] find-first-fail: Passes testsuite.

---
 find-first-fail/find-first-fail | 36 +++++++++++++++++++++++----------
 find-first-fail/testsuite       | 29 ++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/find-first-fail/find-first-fail b/find-first-fail/find-first-fail
index af90362..fbd10b0 100755
--- a/find-first-fail/find-first-fail
+++ b/find-first-fail/find-first-fail
@@ -268,6 +268,7 @@ find-first-fail() {
 	}
 	local a="$1"
 	local b="$2"
+	# TODO if defined memory{$a,$b}: return value
 	shift
 	shift
 	local cmd=("$@")
@@ -279,6 +280,7 @@ find-first-fail() {
 	eval "$not" _inner_run "$quiet"
 	# Postpone exit code
 	local _exit="$?"
+	# TODO memory{$a,$b}="$_exit"
 	rm "$tmp"
 	return "$_exit"
     }
@@ -287,13 +289,16 @@ find-first-fail() {
 	local low=$1
 	local high=$2
 	if [ $low -gt $(($high - 2)) ]; then
+	    # if $low > $high - 0.2: $global_low = $low
 	    global_low=$low
 	    return
 	fi
 	shift
 	shift
 	local middle=$(( ( $low + $high ) / 2 ))
-	if _run_file $middle $global_high "$@" ; then
+	local middledeci=$(( $middle / 10 ))
+	local global_highdeci=$(( $global_high / 10 ))
+	if _run_file  $middledeci $global_highdeci "$@" ; then
 	    low=$middle
 	else
 	    high=$middle
@@ -304,14 +309,17 @@ find-first-fail() {
     _find-high-file() {
 	local low=$1
 	local high=$2
-	if [ $low -gt $(($high - 2)) ]; then
-	    global_high=$high
+	if [ $low -gt $(($high - 5)) ]; then
+	    # if $low > $high - 0.5: $global_high = $high + 0.5
+	    global_high=$(($high + 5))
 	    return
 	fi
 	shift
 	shift
 	local middle=$(( ( $low + $high ) / 2 ))
-	if _run_file $global_low $middle "$@" ; then
+	local middledeci=$(( $middle / 10 ))
+	local global_lowdeci=$(( $global_low / 10 ))
+	if _run_file $global_lowdeci $middledeci "$@" ; then
 	    high=$middle
 	else
 	    low=$middle
@@ -322,23 +330,29 @@ find-first-fail() {
     
     _find_in_file() {
 	# If function(1) = false: run 'not function()' instead
-	local not
-	local global_low=$(($start+1))
 	if [ ! -e "$inputfile" ] ; then
 	    echo "find-first-fail: Error: File not found '$inputfile'" >&2
 	    return 1
 	fi
-	local global_high=$(wc -l < $inputfile)
-	if _run_file "$global_low" "$global_high" "$@" ; then
+	local not
+	local global_low=$(( $start + 1 ))0
+	local global_high=$(wc -l < $inputfile)0
+	local global_lowdeci=$(( $global_low / 10 ))
+	local global_highdeci=$(( $global_high / 10 ))
+	if _run_file "$global_lowdeci" "$global_highdeci" "$@" ; then
 	    not=''
 	else
 	    not='!'
 	fi
-	# Binary search for $global_low
-	_find-low-file $global_low $global_high "$@"
+	# Binary search for minimal $global_high that fails
 	_find-high-file $global_low $global_high "$@"
+	# Binary search for minimal $global_low that fails
+	_find-low-file $global_low $global_high "$@"
+	local global_lowdeci=$(( $global_low / 10 ))
+	local global_highdeci=$(( $global_high / 10 ))
+	# Print the resulting minimal file
 	perl -ne "($start and 1..$start) and print" "$inputfile"
-	perl -ne "$global_low..$global_high and print" "$inputfile"
+	perl -ne "$global_lowdeci..$global_highdeci and print" "$inputfile"
 	unset low high start quiet
     }
 
diff --git a/find-first-fail/testsuite b/find-first-fail/testsuite
index 8b78f8e..e3c1b32 100644
--- a/find-first-fail/testsuite
+++ b/find-first-fail/testsuite
@@ -65,6 +65,35 @@ test_header() {
     find-first-fail -s1 -f $tmp myparser
 }
 
+test_file_start_middle_end() {
+    tmp=`tempfile`
+    testfile() {
+	(echo MyHeader
+	 echo $1
+	 echo 2
+	 echo $2
+	 echo 4
+	 echo $3) > "$tmp"
+    }
+    myparser() { perl -ne 'if($_ > 10) { exit 1 }' "$@"; }
+    export -f myparser
+    echo 'Find 1001'
+    testfile 1001 3 5
+    find-first-fail -s1 -f "$tmp" myparser
+    echo 'Find 1003'
+    testfile 1 1003 5
+    find-first-fail -s1 -f "$tmp" myparser
+    echo 'Find 1005'
+    testfile 1 3 1005
+    find-first-fail -s1 -f "$tmp" myparser
+    echo 'Find 1001/1005'
+    testfile 1001 3 1005
+    find-first-fail -s1 -f "$tmp" myparser
+    echo 'Find 1001/1003/1005'
+    testfile 1001 1003 1005
+    find-first-fail -s1 -f "$tmp" myparser
+}
+
 export -f $(compgen -A function | grep test_)
 compgen -A function | grep test_ | LC_ALL=C sort |
     parallel --timeout 1000% --tag -k --joblog /tmp/jl-`basename $0` '{} 2>&1'