From af7bbb7354f9fc79180193ba397dae91ea89af59 Mon Sep 17 00:00:00 2001
From: marksverdhei <marksverd@gmail.com>
Date: Sat, 27 Jun 2026 19:08:16 +0200
Subject: [PATCH] fix(cf): collapse newlines in send/send-await (preserve
 one-line invariant)
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`cf send "$msg"` wrote the arg verbatim, so a message containing a newline
landed as two physical lines. The chatroom is line-oriented ("Format: Name:
msg") and `await` derives the sender via `tail -n 1 | cut -d: -f1`, so the
wrapped second line — which has no "Name:" prefix — gets parsed as a phantom
message from a sender named after the text. Collapse newlines to spaces in
both `send` and `send-await`.

Adds `test_send_collapses_newlines` (a 2-line message must add exactly one
physical line, prefixed by the sender). Fails against the old code, passes
with the fix; suite 41/41.

Second of the follow-ups noted when #1 was closed as superseded.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 cf         |  7 +++++--
 test_cf.sh | 23 +++++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/cf b/cf
index c6f36a9..dfd08aa 100755
--- a/cf
+++ b/cf
@@ -230,7 +230,10 @@ case "$CMD" in
         [ -z "$1" ] && { echo "Usage: cf send \"message\"" >&2; exit 1; }
         load_session
         [ -z "$JOINED" ] && { echo "Must join first: cf join" >&2; exit 1; }
-        printf '%s: %s\n' "$MYNAME" "$1" >> "$CHATFILE"
+        # Collapse newlines so one send stays one line — the "Name: msg" invariant
+        # that read/await depend on. A literal newline would otherwise land as a
+        # prefix-less second line that await parses as a phantom sender.
+        printf '%s: %s\n' "$MYNAME" "${1//$'\n'/ }" >> "$CHATFILE"
         ;;
 
     await|a|wait|w)
@@ -248,7 +251,7 @@ case "$CMD" in
         [ -z "$1" ] && { echo "Usage: cf send-await \"message\"" >&2; exit 1; }
         load_session
         [ -z "$JOINED" ] && { echo "Must join first: cf join" >&2; exit 1; }
-        printf '%s: %s\n' "$MYNAME" "$1" >> "$CHATFILE"
+        printf '%s: %s\n' "$MYNAME" "${1//$'\n'/ }" >> "$CHATFILE"
         tail -f -n 0 "$CHATFILE" | head -n 1
         ;;
 
diff --git a/test_cf.sh b/test_cf.sh
index 3a7e24d..4a96180 100755
--- a/test_cf.sh
+++ b/test_cf.sh
@@ -542,6 +542,28 @@ test_special_characters_in_message() {
     teardown
 }
 
+test_send_collapses_newlines() {
+    # Regression: a multi-line `send` arg must stay one physical line, or
+    # read/await misparse the wrapped text as a phantom sender (it has no
+    # "Name:" prefix). Newlines collapse to spaces.
+    setup
+    "$CF_PATH" create-room 2>/dev/null || true
+    local name rc=0 before after last
+    name=$("$CF_PATH" register Chatfile)
+    "$CF_PATH" join >/dev/null
+    before=$(wc -l < Chatfile)
+    "$CF_PATH" send "line one
+line two"
+    after=$(wc -l < Chatfile)
+    last=$(tail -n 1 Chatfile)
+    if [ "$((after - before))" -ne 1 ] || [ "$last" != "$name: line one line two" ]; then
+        echo "  multi-line send not collapsed: +$((after - before)) line(s), last='$last'" >&2
+        rc=1
+    fi
+    teardown
+    return $rc
+}
+
 test_multiline_preserved() {
     setup
     "$CF_PATH" create-room 2>/dev/null || true
@@ -685,6 +707,7 @@ echo "Edge Case Tests:"
 run_test "register survives name collisions (set -e)" test_register_survives_name_collisions
 run_test "username uniqueness" test_username_uniqueness
 run_test "special characters in message" test_special_characters_in_message
+run_test "send collapses newlines (one-line invariant)" test_send_collapses_newlines
 run_test "multiline preserved" test_multiline_preserved
 
 echo ""