Skip a lone CR in readLine() instead of grabbing the next byte

testlib.h

@@ -25,7 +25,7 @@
  * Copyright (c) 2005-2026
  */
 
-#define VERSION "0.9.48"
+#define VERSION "0.9.49"
 
 /*
  * Mike Mirzayanov
@@ -63,6 +63,7 @@
  */
 
 const char *latestFeatures[] = {
+        "readLine()/readString(): a CR right before EOF no longer appends a 0xFF byte to the line",
         "Byte 0xFF in input is data, not EOF: EOFC is -1 now, readers return bytes as unsigned char",
         "testlib format()/println() work with using namespace std; call std::format/std::println explicitly for standard formatting",
         "Remove incorrect const attributes",
@@ -4286,6 +4287,7 @@ void InStream::readStringTo(std::string &result) {
                 reader->unreadChar(cur);
                 break;
             }
+            continue;
         }
 
         lastLine = reader->getLine();

tests/test-010_read-line-cr/files/answer.01

@@ -0,0 +1 @@
+abc

tests/test-010_read-line-cr/files/answer.02

@@ -0,0 +1,2 @@
+abcdef
+ghi

tests/test-010_read-line-cr/files/answer.03

@@ -0,0 +1 @@
+abcd

tests/test-010_read-line-cr/files/input.01

@@ -0,0 +1 @@
+1

tests/test-010_read-line-cr/files/output.01

@@ -0,0 +1 @@
+abc

tests/test-010_read-line-cr/files/output.02

@@ -0,0 +1,2 @@
+abcdef
+ghi

tests/test-010_read-line-cr/refs/r1/exit_code

@@ -0,0 +1 @@
+0

tests/test-010_read-line-cr/refs/r1/stderr

@@ -0,0 +1 @@
+ok 1 lines

tests/test-010_read-line-cr/refs/r2/exit_code

@@ -0,0 +1 @@
+0

tests/test-010_read-line-cr/refs/r2/stderr

@@ -0,0 +1 @@
+ok 2 lines

tests/test-010_read-line-cr/refs/r3/exit_code

@@ -0,0 +1 @@
+1

tests/test-010_read-line-cr/refs/r3/stderr

@@ -0,0 +1 @@
+wrong answer line 1: expected 4 bytes 'abcd', found 3 bytes 'abc'

tests/test-010_read-line-cr/run.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+set -eo pipefail
+
+# readLine(): a CR not followed by LF is skipped, a CR right before EOF adds no byte to the line
+
+bash ../scripts/compile src/lines.cpp
+bash ../scripts/test-ref r1 "$VALGRIND" ./lines files/input.01 files/output.01 files/answer.01
+bash ../scripts/test-ref r2 "$VALGRIND" ./lines files/input.01 files/output.02 files/answer.02
+bash ../scripts/test-ref r3 "$VALGRIND" ./lines files/input.01 files/output.01 files/answer.03
+rm -f lines lines.exe

tests/test-010_read-line-cr/src/lines.cpp

@@ -0,0 +1,46 @@
+#include "testlib.h"
+
+using namespace std;
+
+/*
+ * readLine(): LF and CRLF end a line, a CR not followed by LF is skipped,
+ * EOF ends the last line without adding any byte to it.
+ */
+
+static void check(InStream &in, const string &expected, const char *what) {
+    string line = in.readLine();
+    if (line != expected)
+        quitf(_fail, "%s: expected %d bytes '%s', found %d bytes '%s'", what,
+              int(expected.size()), expected.c_str(), int(line.size()), line.c_str());
+    if (!in.eof())
+        quitf(_fail, "%s: not at EOF after the only line", what);
+}
+
+int main(int argc, char *argv[]) {
+    registerTestlibCmd(argc, argv);
+
+    // String streams.
+    InStream a(inf, "abc\r");
+    check(a, "abc", "string 'abc<CR>'");
+    InStream b(inf, "abc\rdef\n");
+    check(b, "abcdef", "string 'abc<CR>def<LF>'");
+    InStream c(inf, "abc\r\n");
+    check(c, "abc", "string 'abc<CR><LF>'");
+    InStream d(inf, "\r");
+    check(d, "", "string '<CR>'");
+
+    // Files: output lines must equal answer lines byte for byte.
+    int lines = 0;
+    while (!ans.eof()) {
+        string j = ans.readLine();
+        string p = ouf.readLine();
+        lines++;
+        if (j != p)
+            quitf(_wa, "line %d: expected %d bytes '%s', found %d bytes '%s'", lines,
+                  int(j.size()), j.c_str(), int(p.size()), p.c_str());
+    }
+    if (!ouf.eof())
+        quitf(_wa, "output has extra data after %d lines", lines);
+
+    quitf(_ok, "%d lines", lines);
+}