Fixed a bug in the print_to_string feature. Fixes #380.

Expanded the unit test for this routine.

Author: jacobwilliams

src/json_value_module.F90

@@ -5761,7 +5761,7 @@ subroutine write_it(advance,comma,space_after_comma)
                 str = str // repeat(space, print_str_chunk_size*n_chunks_to_add)
             end if
             ! append s to str:
-            str(iloc+1:iloc+n-1) = s
+            str(iloc+1:iloc+n) = s
             iloc = iloc + n
 
         end if

src/tests/jf_test_36.F90

@@ -26,6 +26,9 @@ subroutine test_36(error_cnt)
 
     type(json_file) :: my_file
     character(kind=json_CK,len=:),allocatable :: str_in, str_out
+    integer :: i !! counter for number of test cases
+    integer :: j !! counter
+    integer :: n !! size of strings to append
 
     write(error_unit,'(A)') ''
     write(error_unit,'(A)') '================================='
@@ -35,24 +38,78 @@ subroutine test_36(error_cnt)
 
     error_cnt = 0
 
-    ! create a long string:
-    str_in = '{"long_string": "' // repeat('a', 10000) //'"}'
-
-    call my_file%initialize()
-
-    call my_file%load_from_string(str_in)
-
-    if (my_file%failed()) then
-        call my_file%print_error_message(error_unit)
-        error_cnt = error_cnt + 1
-    end if
-    call my_file%print_to_string(str_out)
-    if (my_file%failed()) then
-        call my_file%print_error_message(error_unit)
-        error_cnt = error_cnt + 1
-    end if
-
-    call my_file%destroy()
+    do i = 1, 2
+
+        do n = 0, 200
+
+            str_in = ''
+            str_out = ''
+
+            ! create some long strings:
+            ! [the idea here is to check the chunk
+            !  code for different sized strings]
+            select case (i)
+            case (1)
+                ! one big string
+                str_in = '{"long_string":"' // repeat('a', 10000) //'"}'
+            case (2:)
+                ! a lot of little strings
+                str_in = '{"big_array":['
+                do j = 1, 1000
+                    str_in = str_in // '"' // repeat('a', n) // '"'
+                    if (j<1000) str_in = str_in // ','
+                end do
+                str_in = str_in//']}'
+            end select
+
+            ! don't print extra spaces, so the result will match the input exactly
+            call my_file%initialize(no_whitespace=.true.)
+
+            ! load from the original string:
+            call my_file%load_from_string(str_in)
+            if (my_file%failed()) then
+                call my_file%print_error_message(error_unit)
+                error_cnt = error_cnt + 1
+            end if
+
+            ! now, write it to a new string:
+            call my_file%print_to_string(str_out)
+            if (my_file%failed()) then
+                call my_file%print_error_message(error_unit)
+                error_cnt = error_cnt + 1
+            end if
+            call my_file%destroy()
+
+            ! verify that the strings are the same:
+            if (str_in /= str_out) then
+                write(error_unit,'(A,1X,I2,1X,I4)') ' Error: the strings are not the same for case', i, n
+                error_cnt = error_cnt + 1
+                if (n==2) then
+                    write(error_unit,'(A)') ''
+                    write(error_unit,'(A)') '----str_in:'
+                    write(error_unit,'(A)') str_in
+                    write(error_unit,'(A)') ''
+                    write(error_unit,'(A)') '----str_out:'
+                    write(error_unit,'(A)') str_out
+                    write(error_unit,'(A)') ''
+                    write(error_unit,'(A)') ''
+                    error stop
+                end if
+            end if
+
+            ! now load the string again to verify that it
+            ! printed correctly without errors:
+            call my_file%load_from_string(str_out)
+            if (my_file%failed()) then
+                call my_file%print_error_message(error_unit)
+                error_cnt = error_cnt + 1
+            end if
+
+            if (i==1) exit ! only one for this case
+
+        end do
+
+    end do
 
     if (error_cnt==0) write(error_unit,'(A)') ' Success!'