From 9f8802f49d01eeeb9c7e651af8b3f34258a27acd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 28 Feb 2026 08:26:34 +0000
Subject: [PATCH 1/6] Initial plan


From 33941e4eb38e4a352027c43abab866078a4fd469 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 28 Feb 2026 08:29:56 +0000
Subject: [PATCH 2/6] Fix Date/POSIXt handlers not applied with column.major =
 FALSE

In Ryaml_yoink(), use copyMostAttrib() to preserve class attributes
when extracting single elements from data frame columns for row-major
output. This ensures Date and POSIXt handlers are triggered correctly.

Fixes #161

Co-authored-by: krlmlr <1741643+krlmlr@users.noreply.github.com>
---
 _codeql_detected_source_root  |  1 +
 src/r_emit.c                  |  3 +++
 tests/testthat/test-as_yaml.R | 24 ++++++++++++++++++++++++
 3 files changed, 28 insertions(+)
 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..945c9b4
--- /dev/null
+++ b/_codeql_detected_source_root
@@ -0,0 +1 @@
+.
\ No newline at end of file
diff --git a/src/r_emit.c b/src/r_emit.c
index 4f9b8ea..498ffe4 100644
--- a/src/r_emit.c
+++ b/src/r_emit.c
@@ -300,6 +300,9 @@ static SEXP Ryaml_yoink(SEXP s_vec, int index)
       RAW(s_tmp)[0] = RAW(s_vec)[index];
       break;
   }
+  if (!factor) {
+    copyMostAttrib(s_vec, s_tmp);
+  }
   UNPROTECT(1);
 
   return s_tmp;
diff --git a/tests/testthat/test-as_yaml.R b/tests/testthat/test-as_yaml.R
index f07dadf..90201a3 100644
--- a/tests/testthat/test-as_yaml.R
+++ b/tests/testthat/test-as_yaml.R
@@ -479,3 +479,27 @@ test_that("no dots at end", {
   result <- yaml::as.yaml(list(eol = "\n", a = 1), line.sep = "\n")
   expect_equal(result, "eol: |2+\n\na: 1.0\n")
 })
+
+test_that("Date handler works with column.major = FALSE", {
+  x <- data.frame(date = as.Date(c("2012-10-10", "2014-03-28")))
+  handler <- list(Date = function(x) as.character(x))
+
+  result_col <- as.yaml(x, handlers = handler, column.major = TRUE)
+  result_row <- as.yaml(x, handlers = handler, column.major = FALSE)
+
+  expect_equal(result_col, "date:\n- '2012-10-10'\n- '2014-03-28'\n")
+  expect_equal(result_row, "- date: '2012-10-10'\n- date: '2014-03-28'\n")
+})
+
+test_that("POSIXct handler works with column.major = FALSE", {
+  x <- data.frame(
+    time = as.POSIXct(c("2012-10-10", "2014-03-28"), tz = "UTC")
+  )
+  handler <- list(POSIXct = function(x) format(x, "%Y-%m-%d"))
+
+  result_col <- as.yaml(x, handlers = handler, column.major = TRUE)
+  result_row <- as.yaml(x, handlers = handler, column.major = FALSE)
+
+  expect_equal(result_col, "time:\n- '2012-10-10'\n- '2014-03-28'\n")
+  expect_equal(result_row, "- time: '2012-10-10'\n- time: '2014-03-28'\n")
+})

From 6175d251a62a0b38dbc07ace32d813776b2d2e1b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 28 Feb 2026 10:01:17 +0000
Subject: [PATCH 3/6] Simplify Ryaml_yoink: remove factor special-casing,
 always copyMostAttrib

Remove the factor-specific code path that converted factors to STRSXP
in Ryaml_yoink(). Instead, always copy the integer value and call
copyMostAttrib() unconditionally. The existing emit_factor() in
emit_object() handles factor resolution correctly.

This ensures factor handlers work with column.major = FALSE, just
like Date and POSIXt handlers. Added tests for factor columns.

Co-authored-by: krlmlr <1741643+krlmlr@users.noreply.github.com>
---
 src/r_emit.c                  | 25 +++++--------------------
 tests/testthat/test-as_yaml.R | 13 +++++++++++++
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/src/r_emit.c b/src/r_emit.c
index 498ffe4..2f74cf9 100644
--- a/src/r_emit.c
+++ b/src/r_emit.c
@@ -261,31 +261,18 @@ static yaml_scalar_style_t Ryaml_string_style(SEXP s_obj)
 /* Take a vector and an index and return another vector of size 1 */
 static SEXP Ryaml_yoink(SEXP s_vec, int index)
 {
-  SEXP s_tmp = NULL, s_levels = NULL;
-  int type = 0, factor = 0, level_idx = 0;
+  SEXP s_tmp = NULL;
+  int type = 0;
 
   type = TYPEOF(s_vec);
-  factor = type == INTSXP && Ryaml_has_class(s_vec, "factor");
-  PROTECT(s_tmp = allocVector(factor ? STRSXP : type, 1));
+  PROTECT(s_tmp = allocVector(type, 1));
 
   switch(type) {
     case LGLSXP:
       LOGICAL(s_tmp)[0] = LOGICAL(s_vec)[index];
       break;
     case INTSXP:
-      if (factor) {
-        s_levels = getAttrib(s_vec, R_LevelsSymbol);
-        level_idx = INTEGER(s_vec)[index];
-        if (level_idx == NA_INTEGER || level_idx < 1 || level_idx > LENGTH(s_levels)) {
-          SET_STRING_ELT(s_tmp, 0, NA_STRING);
-        }
-        else {
-          SET_STRING_ELT(s_tmp, 0, STRING_ELT(s_levels, level_idx - 1));
-        }
-      }
-      else {
-        INTEGER(s_tmp)[0] = INTEGER(s_vec)[index];
-      }
+      INTEGER(s_tmp)[0] = INTEGER(s_vec)[index];
       break;
     case REALSXP:
       REAL(s_tmp)[0] = REAL(s_vec)[index];
@@ -300,9 +287,7 @@ static SEXP Ryaml_yoink(SEXP s_vec, int index)
       RAW(s_tmp)[0] = RAW(s_vec)[index];
       break;
   }
-  if (!factor) {
-    copyMostAttrib(s_vec, s_tmp);
-  }
+  copyMostAttrib(s_vec, s_tmp);
   UNPROTECT(1);
 
   return s_tmp;
diff --git a/tests/testthat/test-as_yaml.R b/tests/testthat/test-as_yaml.R
index 90201a3..2403cf7 100644
--- a/tests/testthat/test-as_yaml.R
+++ b/tests/testthat/test-as_yaml.R
@@ -503,3 +503,16 @@ test_that("POSIXct handler works with column.major = FALSE", {
   expect_equal(result_col, "time:\n- '2012-10-10'\n- '2014-03-28'\n")
   expect_equal(result_row, "- time: '2012-10-10'\n- time: '2014-03-28'\n")
 })
+
+test_that("factor column works with column.major = FALSE", {
+  x <- data.frame(x = factor(c("a", "b", "c")))
+  result <- as.yaml(x, column.major = FALSE)
+  expect_equal(result, "- x: a\n- x: b\n- x: c\n")
+})
+
+test_that("factor handler works with column.major = FALSE", {
+  x <- data.frame(x = factor(c("a", "b", "c")))
+  handler <- list(factor = function(x) paste0("level_", x))
+  result <- as.yaml(x, handlers = handler, column.major = FALSE)
+  expect_equal(result, "- x: level_a\n- x: level_b\n- x: level_c\n")
+})

From 67f6edaed006e14da993a71491b4c01451ec64d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <krlmlr@users.noreply.github.com>
Date: Sat, 28 Feb 2026 12:09:48 +0100
Subject: [PATCH 4/6] Deleted

---
 _codeql_detected_source_root | 1 -
 1 file changed, 1 deletion(-)
 delete mode 120000 _codeql_detected_source_root

diff --git a/_codeql_detected_source_root b/_codeql_detected_source_root
deleted file mode 120000
index 945c9b4..0000000
--- a/_codeql_detected_source_root
+++ /dev/null
@@ -1 +0,0 @@
-.
\ No newline at end of file

From 547d7ac1560bd07ab042fb4bda26d3a7a2f05789 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <krlmlr@users.noreply.github.com>
Date: Sat, 28 Feb 2026 12:09:55 +0100
Subject: [PATCH 5/6] Ignored

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 2b9e9cb..abb70d3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ yaml_*.tar.gz
 *.Rproj
 docs
 inst/doc
+_codeql_detected_source_root

From f4f1798add3ae185f21e75a463fdafec1c4959a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <krlmlr@users.noreply.github.com>
Date: Sat, 28 Feb 2026 12:12:21 +0100
Subject: [PATCH 6/6] NEWS

---
 NEWS.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index bf24868..f624bba 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 # yaml (development version)
 
+* Apply handlers also with `column.major = FALSE` (#164, @krlmlr).
+
+# yaml 2.3.12
+
 * Fixes for C API compliance.
 
 * Switched from `CHANGELOG` to `NEWS.md`.