From fee05f769d4e5aaaf36fefd7b6c244b863fd1768 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 25 Jan 2026 10:32:06 +0000
Subject: [PATCH] Fix C module to match Elisp behavior for last-line overflow
 handling

When is_last && ideal > line_width, the C module now correctly
triggers force break logic, matching ekp--dp-cache-elisp behavior.
This ensures consistent results between C module and pure Elisp paths.

Co-authored-by: Kinneyzhang <38454496+Kinneyzhang@users.noreply.github.com>
---
 _codeql_detected_source_root |  1 +
 ekp_c/ekp_kp.c               | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)
 create mode 120000 _codeql_detected_source_root

diff --git a/_codeql_detected_source_root b/_codeql_detected_source_root
new file mode 120000
index 0000000..fe661d3
--- /dev/null
+++ b/_codeql_detected_source_root
@@ -0,0 +1 @@
+./ekp_c
\ No newline at end of file
diff --git a/ekp_c/ekp_kp.c b/ekp_c/ekp_kp.c
index 4504bc6..4229432 100644
--- a/ekp_c/ekp_kp.c
+++ b/ekp_c/ekp_kp.c
@@ -166,8 +166,10 @@ static void process_dp_range(void *arg)
                 max_w += p->hyphen_width;
             }
 
-            /* Too long? */
-            if (min_w > line_width) {
+            /* Too long? Also handle is_last && ideal > line_width.
+             * This matches Elisp's ekp--dp-cache-elisp which breaks when
+             * content won't fit even at the end of a paragraph. */
+            if (min_w > line_width || (is_last && ideal > line_width)) {
                 /* Force break if nothing else found */
                 if (k > 1 && work->demerits[k - 1] >= EKP_INFINITY) {
                     int32_t rest = line_width - (p->ideal_prefix[k - 1] -
@@ -497,8 +499,10 @@ ekp_result_t *ekp_break_with_prefixes(
                 max_w += hyphen_width;
             }
 
-            /* Too long? Force break at k-1 if no valid break found yet */
-            if (min_w > line_width) {
+            /* Too long? Also handle is_last && ideal > line_width.
+             * This matches Elisp's ekp--dp-cache-elisp which breaks when
+             * content won't fit even at the end of a paragraph. */
+            if (min_w > line_width || (is_last && ideal > line_width)) {
                 if (k > i + 1 && demerits[k - 1] >= EKP_INFINITY) {
                     /* Force break at previous position with high penalty */
                     int32_t prev_ideal = ideal_prefix[k - 1] - ideal_prefix[i] - lead_ideal;