Windows: os.get_raw_line trim right `\r\n` interpolation unhandled exception

[jorgeluismireles]

Describe the bug

New bug derived from issue #23764

We read a file line by line with os.get_raw_line and use .trim_right('\r\n') and after print interpolated we get an Unhandled Exception with rows complex and large. Tested on windows with both tcc and mingw.

Reproduction Steps

module main

import os

fn main() {
	mut i:= 0
	for {
		i += 1
		mut line := os.get_raw_line()
		if line.len == 0 {
			break
		}
		line2 := line.trim_right('\r\n')
		// println('${i}: ${line2.len}') OK prints n: 1034 n=1,2,3
		println('${i}: ${line2}') // error
	}
}

Note: the size of the line is calculated and printed ok but not he whole line content.

Expected Behavior

Print three lines with text

1: ...
2: ...
3: ...

Current Behavior

We pass the file using window command C:\type {file} | {v app}

C:\Users\jmireles\issues>type yyy.txt | v run issue.v
1: {"@timestamp":"2025-02-19T15:45:49.746Z","@version":"1","message":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","logger_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","thread_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","level":"INFO","level_value":20000,"uid":"","request_id":"xxxxxx","session_log_id":"xxxxxxxxxxx","ip":"xxx.xxx.xxx.xxx","referer":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx012345678901234567890123456","processing_time_ms":0,"method":"GET","content_type":"text/javascript","query":null,"type":"xxxxxxxxxxxxxxxx","request_uri":"/pub/js/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js","status":200}
Unhandled Exception 0x148f8b0
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:4468: at print_backtrace_skipping_top_frames_tcc: Backtrace
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:4454: by print_backtrace_skipping_top_frames
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:4991: by unhandled_exception_handler
7ffa52d13556 : by ???
004265eb : at ???: RUNTIME ERROR: invalid memory access
004266c9 : by ???
004266f4 : by ???
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:4785: by malloc_noscan
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:4890: by memdup_noscan
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:2378: by strings__Builder_str
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:6405: by str_intp
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:6661: by main__main
C:/Users/jmireles/AppData/Local/Temp/v_0/win_23764.01JMWADPQ468AA0BXK71T7R3FY.tmp.c:6689: by wmain
00437908 : by ???
00437a6b : by ???
7ffa515fe8d7 : by ???

Fails with both tcc and mingw

yyy.txt data file (same of derived issue mentioned above):

{"@timestamp":"2025-02-19T15:45:49.746Z","@version":"1","message":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","logger_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","thread_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","level":"INFO","level_value":20000,"uid":"","request_id":"xxxxxx","session_log_id":"xxxxxxxxxxx","ip":"xxx.xxx.xxx.xxx","referer":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx012345678901234567890123456","processing_time_ms":0,"method":"GET","content_type":"text/javascript","query":null,"type":"xxxxxxxxxxxxxxxx","request_uri":"/pub/js/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js","status":200}
{"@timestamp":"2025-02-19T15:45:49.746Z","@version":"1","message":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","logger_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","thread_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","level":"INFO","level_value":20000,"uid":"","request_id":"xxxxxx","session_log_id":"xxxxxxxxxxx","ip":"xxx.xxx.xxx.xxx","referer":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","processing_time_ms":0,"method":"GET","content_type":"text/javascript","query":null,"type":"xxxxxxxxxxxxxxxx","request_uri":"/pub/js/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js","status":200}
{"@timestamp":"2025-02-19T15:45:49.746Z","@version":"1","message":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","logger_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","thread_name":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","level":"INFO","level_value":20000,"uid":"","request_id":"xxxxxx","session_log_id":"xxxxxxxxxxx","ip":"xxx.xxx.xxx.xxx","referer":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","processing_time_ms":0,"method":"GET","content_type":"text/javascript","query":null,"type":"xxxxxxxxxxxxxxxx","request_uri":"/pub/js/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.js","status":200}

Simpler files does not fail, seems related with the complexity/size of the rows of this test file.

Possible Solution

No response

Additional Information/Context

No response

V version

30ececc

Environment details (OS name and version, etc.)

V full version	V 0.4.9 30ececc.1cb76c9
OS	windows, Microsoft Windows 11 Pro 26100 64-bit
Processor	12 cpus, 64bit, little endian, 13th Gen Intel(R) Core(TM) i7-1355U
Memory	9.64GB/15.68GB
V executable	C:\Users\jmireles\v\v.exe
V last modified time	2025-02-24 15:41:43
V home dir	OK, value: C:\Users\jmireles\v
VMODULES	OK, value: C:\Users\jmireles.vmodules
VTMP	OK, value: C:\Users\jmireles\AppData\Local\Temp\v_0
Current working dir	OK, value: C:\Users\jmireles\issues
Git version	git version 2.47.1.windows.1
V git status	1cb76c9
.git/config present	true
cc version	N/A
gcc version	gcc (MinGW-W64 x86_64-ucrt-posix-seh, built by Brecht Sanders, r2) 14.2.0
clang version	(built by Brecht Sanders, r2) clang version 19.1.1
msvc version	N/A
tcc version	tcc version 0.9.27 (x86_64 Windows)
tcc git status	thirdparty-windows-amd64 b425ac82
emcc version	N/A
glibc version	N/A

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[huly-for-github]

Connected to Huly®: V_0.6-22212

[DamianFekete]

Hi @jorgeluismireles, I didn't manage to respond sooner in the other issue, but I don't think that trim_right causes any issues.
It caused an issue because the memory was already corrupted.
When you removed the call to trim_right the program didn't crash anymore, but I remember that when I removed some print statements the program "seemed" to work fine (although the memory/stack was still corrupted).

[jorgeluismireles]

Hello DamianFekete. I opened this issue as spytheman recommendation. Think is better to have it in case something new could be fixed. Yes, I thing the big rows caused the problem but let see. Being specific of Windows and requiring extra files is more difficult to reproduce, test and solve.

[kbkpbot]

This is because under windows, get_raw_line has a max 256/512 bytes buffer. So there is a buffer overflow bug here.

// get_raw_line returns a one-line string from stdin along with '\n' if there is any.
pub fn get_raw_line() string {
	$if windows {
		unsafe {
			max_line_chars := 256
			buf := malloc_noscan(max_line_chars * 2)
			h_input := C.GetStdHandle(C.STD_INPUT_HANDLE)
			mut bytes_read := u32(0)
			if is_atty(0) > 0 {
				x := C.ReadConsole(h_input, buf, max_line_chars * 2, voidptr(&bytes_read),
					0)
				if !x {
					return tos(buf, 0)
				}
				return string_from_wide2(&u16(buf), int(bytes_read))
			}
			mut offset := 0    
			for {                                      // this will cause buffer overflow when input many chars......
				pos := buf + offset
				res := C.ReadFile(h_input, pos, 1, voidptr(&bytes_read), 0)
				if !res && offset == 0 {
					return tos(buf, 0)
				}
				if !res || bytes_read == 0 {
					break
				}
				if *pos == `\n` {
					offset++
					break
				}
				offset++
			}
			return buf.vstring_with_len(offset)
		}
	} $else {

[JalonSolov]

Fixed in #23816