diff --git a/src/stdlib_stringlist_type.f90 b/src/stdlib_stringlist_type.f90
index 78cfb69d3..2ecddf0cb 100644
--- a/src/stdlib_stringlist_type.f90
+++ b/src/stdlib_stringlist_type.f90
@@ -642,23 +642,29 @@ subroutine insert_before_stringlist_int_impl( list, idxn, slist )
type(stringlist_type), intent(in) :: slist
integer :: i
- integer :: work_idxn, idxnew
- integer :: pre_length, post_length
+ integer :: work_idxn, inew
+ integer :: pre_length, post_length, temp
- work_idxn = idxn
pre_length = slist%len()
- call insert_before_empty_positions( list, work_idxn, pre_length )
- post_length = slist%len()
+ if (pre_length > 0) then
+ work_idxn = idxn
- do i = 1, min( work_idxn - 1, pre_length )
- idxnew = work_idxn + i - 1
- list%stringarray(idxnew) = slist%stringarray(i)
- end do
+ call insert_before_empty_positions( list, work_idxn, pre_length )
+ post_length = slist%len()
- do i = work_idxn + post_length - pre_length, post_length
- idxnew = work_idxn + i - post_length + pre_length - 1
- list%stringarray(idxnew) = slist%stringarray(i)
- end do
+ inew = work_idxn
+ temp = min( work_idxn - 1, pre_length )
+ do i = 1, temp
+ list%stringarray(inew) = slist%stringarray(i)
+ inew = inew + 1
+ end do
+
+ temp = work_idxn + post_length - pre_length
+ do i = temp, post_length
+ list%stringarray(inew) = slist%stringarray(i)
+ inew = inew + 1
+ end do
+ end if
end subroutine insert_before_stringlist_int_impl
diff --git a/src/tests/stringlist/test_insert_at.f90 b/src/tests/stringlist/test_insert_at.f90
index 231ac0e9c..aa1f01c13 100644
--- a/src/tests/stringlist/test_insert_at.f90
+++ b/src/tests/stringlist/test_insert_at.f90
@@ -1,9 +1,10 @@
! SPDX-Identifier: MIT
module test_insert_at
use stdlib_error, only: check
- use stdlib_string_type, only: string_type, operator(//), operator(==)
+ use stdlib_string_type, only: string_type, operator(//), operator(==), char, operator(/=)
use stdlib_stringlist_type, only: stringlist_type, fidx, bidx, list_head, list_tail, operator(==)
use stdlib_strings, only: to_string
+ use stdlib_optval, only: optval
implicit none
contains
@@ -351,24 +352,85 @@ subroutine test_constructor
end subroutine test_constructor
+ subroutine test_insert_at_same_list
+ type(stringlist_type) :: work_list
+ type(stringlist_type) :: temp_list
+ integer :: i
+ integer, parameter :: first = -100
+ integer, parameter :: last = 100
+
+ write (*,*) "test_insert_at_same_list: Starting work_list!"
+
+ call work_list%insert_at( list_head, work_list )
+ call work_list%insert_at( list_tail, work_list )
+
+ do i = -10, 10
+ call work_list%insert_at( fidx(i), work_list )
+ call work_list%insert_at( bidx(i), work_list )
+
+ end do
+
+ call compare_list( work_list, 0, 0, 13 )
+ call check( work_list%len() == 0, "test_insert_at_same_list: empty list insertion")
+
+ do i = first, last
+ call work_list%insert_at( list_tail, string_type( to_string(i) ) )
+ call check(string_type( to_string(i) ) /= "", "There is something wrong with this")
+ end do
+ temp_list = work_list
+
+ call work_list%insert_at( list_head, work_list )
+ ! call compare_list( work_list, first, last + 1, 14, to=last - first + 1 )
+ call compare_list( work_list, first, last + 1, 15, from=last - first + 2 )
+
+ work_list = temp_list
+ call work_list%insert_at( list_tail, work_list )
+ call compare_list( work_list, first, last + 1, 16, to=last - first + 1 )
+ call compare_list( work_list, first, last + 1, 17, from=last - first + 2 )
+
+ work_list = temp_list
+ call compare_list( work_list, first, last + 1, 18 )
+
+ write (*,*) "test_insert_at_same_list: Starting temp_list!"
+
+ do i = 1, last - first + 2
+ temp_list = work_list
+ call temp_list%insert_at( fidx(i), temp_list )
+
+ call compare_list( temp_list, first, first + i - 1, 19, to=i - 1 )
+ call compare_list( temp_list, first, last + 1, 20, from=i, to=i + last - first )
+ call compare_list( temp_list, first + i - 1, last + 1, 21, from=i + last - first + 1 )
+
+ end do
+
+ end subroutine test_insert_at_same_list
+
! compares input stringlist 'list' with an array of consecutive integers
! array is 'first' inclusive and 'last' exclusive
- subroutine compare_list(list, first, last, call_number)
+ subroutine compare_list(list, first, last, call_number, from, to)
type(stringlist_type), intent(in) :: list
integer, intent(in) :: first, last, call_number
- integer :: i, j
+ integer, intent(in), optional :: from, to
+ integer :: i, j, k, work_from, work_to, length
+
+ length = list%len()
+ work_from = optval( from, 1 )
+ work_to = optval( to, length )
- call check( abs( last - first ) == list%len(), "compare_list: length mis-match&
+ call check( abs( last - first ) == max( 0, work_to - work_from + 1 ), "compare_list: length mis-match&
& call_number " // to_string( call_number ) )
j = merge(-1, 1, last < first)
- do i = 1, list%len()
- call check( list%get( fidx(i) ) == to_string( first + ( ( i - 1 ) * j ) ), &
+ do i = work_from, work_to
+ call check( list%get( fidx(i) ) == to_string( first + ( ( i - work_from ) * j ) ), &
& "compare_list: call_number " // to_string( call_number ) &
- & // " fidx( " // to_string( i ) // " )")
- call check( list%get( bidx(i) ) == to_string( last - ( i * j ) ), &
+ & // " fidx( " // to_string( i ) // " )" )
+
+ k = length - ( work_to - ( i - work_from ) ) + 1
+ call check( list%get( bidx(k) ) == &
+ & to_string( last - ( ( i - work_from + 1 ) * j ) ), &
& "compare_list: call_number " // to_string( call_number ) &
- & // " bidx( " // to_string( i ) // " )")
+ & // " bidx( " // to_string( k ) // " )" )
end do
end subroutine compare_list
@@ -385,6 +447,7 @@ program tester
call test_insert_at_string_3
call test_insert_at_array
call test_insert_at_list
+ call test_insert_at_same_list
call test_constructor
end program tester