From 367e597c6a0e78c36f7c3553c20597962d4608f4 Mon Sep 17 00:00:00 2001
From: Jay Hemnani <193022578+jayhemnani9910@users.noreply.github.com>
Date: Fri, 23 Oct 2026 03:32:12 +0530
Subject: [PATCH 1/2] pr: stop merged output after the last line without a page
 trailer

With -m and -t, -T or -F, the merged files were padded with empty rows to the full page length, so two two-line files gave 56 lines; GNU pr prints the two lines.
---
 src/uu/pr/src/pr.rs      |  9 +++++++++
 tests/by-util/test_pr.rs | 13 +++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/uu/pr/src/pr.rs b/src/uu/pr/src/pr.rs
index fd9c9cd1603..aa2eb5617e1 100644
--- a/src/uu/pr/src/pr.rs
+++ b/src/uu/pr/src/pr.rs
@@ -1502,6 +1502,15 @@ fn write_columns(
 
     let blank_line = FileLine::default();
     for row in table {
+        // Merged files are padded with empty cells to fill the page; once
+        // every file has run out there is nothing left to print without a
+        // page trailer to pad for.
+        if merge
+            && row.iter().all(Option::is_none)
+            && (feed_line_present || !options.display_header_and_trailer)
+        {
+            break;
+        }
         // On a page that is not completely filled the last row stops part way
         // through, and its final cell must not be followed by a column
         // separator. Merging prints an empty cell for every column instead, so
diff --git a/tests/by-util/test_pr.rs b/tests/by-util/test_pr.rs
index 9f4f050723d..c6c815a3820 100644
--- a/tests/by-util/test_pr.rs
+++ b/tests/by-util/test_pr.rs
@@ -701,6 +701,19 @@ fn test_join_lines_keeps_column_separator() {
         .stdout_is("1\t3\n2\t4\n");
 }
 
+#[test]
+fn test_merge_stops_after_last_line_without_header() {
+    // without a page trailer there is nothing to pad to: like GNU pr, stop
+    // after the last merged line (-F still prints the 5 header lines and a form feed)
+    for (flag, lines) in [("-t", 2), ("-T", 2), ("-F", 8)] {
+        let (at, mut ucmd) = at_and_ucmd!();
+        at.write("one", "a\nb\n");
+        at.write("two", "c\nd\n");
+        let result = ucmd.args(&["-m", flag, "one", "two"]).succeeds();
+        assert_eq!(result.stdout_str().lines().count(), lines, "{flag}");
+    }
+}
+
 #[test]
 fn test_value_for_number_lines() {
     // *5 is of the form [SEP[NUMBER]] so is accepted and succeeds

From 8df73852cbc5caeb542380edf17e6d8cb44d3c48 Mon Sep 17 00:00:00 2001
From: Jay Hemnani <193022578+jayhemnani9910@users.noreply.github.com>
Date: Sun, 25 Oct 2026 13:25:22 +0530
Subject: [PATCH 2/2] pr: name the no-trailer condition, check the exact merged
 output

---
 src/uu/pr/src/pr.rs      | 15 +++++----------
 tests/by-util/test_pr.rs | 16 +++++++++++++---
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/src/uu/pr/src/pr.rs b/src/uu/pr/src/pr.rs
index aa2eb5617e1..3d830d909a7 100644
--- a/src/uu/pr/src/pr.rs
+++ b/src/uu/pr/src/pr.rs
@@ -1501,14 +1501,12 @@ fn write_columns(
     };
 
     let blank_line = FileLine::default();
+    // Without a page trailer there is nothing to pad the page out to.
+    let no_trailer = feed_line_present || !options.display_header_and_trailer;
     for row in table {
         // Merged files are padded with empty cells to fill the page; once
-        // every file has run out there is nothing left to print without a
-        // page trailer to pad for.
-        if merge
-            && row.iter().all(Option::is_none)
-            && (feed_line_present || !options.display_header_and_trailer)
-        {
+        // every file has run out there is nothing left to print.
+        if merge && no_trailer && row.iter().all(Option::is_none) {
             break;
         }
         // On a page that is not completely filled the last row stops part way
@@ -1541,10 +1539,7 @@ fn write_columns(
         // The last row of a partly filled page has content in its leading
         // columns and nothing in the rest, so it still needs to be terminated.
         // Only a row without any content at all means the page ran out.
-        if cells_written == 0
-            && not_found_break
-            && (feed_line_present || !options.display_header_and_trailer)
-        {
+        if cells_written == 0 && not_found_break && no_trailer {
             break;
         }
         writer.write_all(line_separator)?;
diff --git a/tests/by-util/test_pr.rs b/tests/by-util/test_pr.rs
index c6c815a3820..af32d3d30be 100644
--- a/tests/by-util/test_pr.rs
+++ b/tests/by-util/test_pr.rs
@@ -705,12 +705,22 @@ fn test_join_lines_keeps_column_separator() {
 fn test_merge_stops_after_last_line_without_header() {
     // without a page trailer there is nothing to pad to: like GNU pr, stop
     // after the last merged line (-F still prints the 5 header lines and a form feed)
-    for (flag, lines) in [("-t", 2), ("-T", 2), ("-F", 8)] {
+    // -J keeps the columns from being padded, so the lines are short
+    let body = "a\tc\nb\td\n";
+    let header = format!("\n\nX{}Page 1\n\n\n", " ".repeat(65));
+    for (args, expected) in [
+        (vec!["-J", "-t"], body.to_string()),
+        (vec!["-J", "-T"], body.to_string()),
+        (vec!["-J", "-F", "-D", "X"], format!("{header}{body}\x0c")),
+    ] {
         let (at, mut ucmd) = at_and_ucmd!();
         at.write("one", "a\nb\n");
         at.write("two", "c\nd\n");
-        let result = ucmd.args(&["-m", flag, "one", "two"]).succeeds();
-        assert_eq!(result.stdout_str().lines().count(), lines, "{flag}");
+        ucmd.arg("-m")
+            .args(&args)
+            .args(&["one", "two"])
+            .succeeds()
+            .stdout_is(expected);
     }
 }