From ecb135d1e61d16acac808e5bcab7c623928bdcff Mon Sep 17 00:00:00 2001
From: Jan Midtgaard <mail@janmidtgaard.dk>
Date: Fri, 5 Jan 2024 17:59:09 +0100
Subject: [PATCH] Adjust output{_char,_string,_bytes,,_substring} to reflect nl
 translation on MinGW+Cygwin

---
 src/io/stm_tests.ml | 47 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 34 insertions(+), 13 deletions(-)

diff --git a/src/io/stm_tests.ml b/src/io/stm_tests.ml
index 2def6b7a..cfbe6b00 100644
--- a/src/io/stm_tests.ml
+++ b/src/io/stm_tests.ml
@@ -87,6 +87,9 @@ struct
 
   let init_state  = Closed 0L
 
+  let count_nls s =
+    String.fold_right (fun c count -> if c = '\n' then 1+count else count) s 0
+
   let next_state c s = match c,s with
     | Open_text, Closed _l ->
       Open { position = 0L;
@@ -123,30 +126,45 @@ struct
     | Set_buffered b, Open { position; length; buffered = _; binary_mode } ->
       Open { position; length; buffered = b; binary_mode }
     (* output on open Out_channel *)
-    | Output_char _, Open { position; length; buffered; binary_mode }
+    | Output_char c, Open { position; length; buffered; binary_mode } ->
+      let len = (* Windows text mode maps '\n' to "\r\n" *)
+        if (Sys.win32 || Sys.cygwin) && not binary_mode && c = '\n' then 2L else 1L in
+      Open { position = Int64.add position len;
+             length   = Int64.add length len;
+             buffered;
+             binary_mode; }
     | Output_byte _, Open { position; length; buffered; binary_mode } ->
       Open { position = Int64.succ position;
              length = Int64.succ length;
              buffered;
              binary_mode; }
     | Output_string str, Open { position; length; buffered; binary_mode } ->
-       let len = Int64.of_int (String.length str) in
-       Open { position = Int64.add position len;
-              length   = Int64.add length len;
-              buffered;
-              binary_mode; }
+      let len = (* Windows text mode maps '\n' to "\r\n" *)
+        if (Sys.win32 || Sys.cygwin) && not binary_mode
+        then Int64.of_int (String.length str + count_nls str)
+        else Int64.of_int (String.length str) in
+      Open { position = Int64.add position len;
+             length   = Int64.add length len;
+             buffered;
+             binary_mode; }
     | Output_bytes b, Open { position; length; buffered; binary_mode } ->
-       let len = Int64.of_int (Bytes.length b) in
-       Open { position = Int64.add position len;
-              length   = Int64.add length len;
-              buffered;
-              binary_mode; }
+      let len = (* Windows text mode maps '\n' to "\r\n" *)
+        if (Sys.win32 || Sys.cygwin) && not binary_mode
+        then Int64.of_int (Bytes.length b + count_nls (String.of_bytes b))
+        else Int64.of_int (Bytes.length b) in
+      Open { position = Int64.add position len;
+             length   = Int64.add length len;
+             buffered;
+             binary_mode; }
     | Output (b,p,l), Open { position; length; buffered; binary_mode } ->
       let bytes_len = Bytes.length b in
       if p < 0 || p >= bytes_len || l < 0 || p+l > bytes_len
       then s
       else
-        let len = Int64.of_int l in
+        let len = (* Windows text mode maps '\n' to "\r\n" *)
+          if (Sys.win32 || Sys.cygwin) && not binary_mode
+          then Int64.of_int (l + count_nls String.(sub (of_bytes b) p l))
+          else Int64.of_int l in
         Open { position = Int64.add position len;
                length   = Int64.add length len;
                buffered;
@@ -156,7 +174,10 @@ struct
       if p < 0 || p >= str_len || l < 0 || p+l > str_len
       then s
       else
-        let len = Int64.of_int l in
+        let len = (* Windows text mode maps '\n' to "\r\n" *)
+          if (Sys.win32 || Sys.cygwin) && not binary_mode
+          then Int64.of_int (l + count_nls (String.sub str p l))
+          else Int64.of_int l in
         Open { position = Int64.add position len;
                length   = Int64.add length len;
                buffered;