patch: also write reject file when outputting to stdout

src/patch.cpp

@@ -590,6 +590,20 @@ int process_patch(const Options& options)
 
         Result result = apply_patch(tmp_out_file, reject_writer, input_lines, patch, options, out);
 
+        if (result.failed_hunks != 0) {
+            had_failure = true;
+            const char* reason = result.was_skipped ? "ignored" : "FAILED";
+            inform_hunks_failed(out, reason, patch.hunks, result.failed_hunks);
+            if (!options.dry_run) {
+                const auto reject_file = reject_path(options, output_file);
+                out << " -- saving rejects to file " << reject_file;
+
+                File file(reject_file, mode | std::ios::trunc);
+                tmp_reject_file.write_entire_contents_to(file);
+            }
+            out << '\n';
+        }
+
         if (output_to_stdout) {
             // Nothing else to do other than write to stdout :^)
             tmp_out_file.write_entire_contents_to(stdout);
@@ -600,19 +614,7 @@ int process_patch(const Options& options)
                 write_patched_result_to_file(patch, output_file, permission_result, mode, deferred_writer, tmp_out_file);
             }
 
-            if (result.failed_hunks != 0) {
-                had_failure = true;
-                const char* reason = result.was_skipped ? "ignored" : "FAILED";
-                inform_hunks_failed(out, reason, patch.hunks, result.failed_hunks);
-                if (!options.dry_run) {
-                    const auto reject_file = reject_path(options, output_file);
-                    out << " -- saving rejects to file " << reject_file;
-
-                    File file(reject_file, mode | std::ios::trunc);
-                    tmp_reject_file.write_entire_contents_to(file);
-                }
-                out << '\n';
-            } else {
+            if (result.failed_hunks == 0) {
                 if (!options.dry_run && patch.operation == Operation::Rename)
                     remove_file_and_empty_parent_folders(file_to_patch);
 

tests/test_basic.cpp

@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: BSD-3-Clause
-// Copyright 2022-2023 Shannon Booth <[email protected]>
+// Copyright 2022-2024 Shannon Booth <[email protected]>
 
 #include <patch/file.h>
 #include <patch/process.h>
@@ -329,6 +329,40 @@ PATCH_TEST(basic_patch_with_dry_run_to_stdout)
     EXPECT_FILE_EQ("to_patch", to_patch);
 }
 
+PATCH_TEST(failed_patch_to_stdout)
+{
+    const std::string patch = R"(--- 1	2022-06-26 12:22:22.161398905 +1200
++++ 2	2022-06-26 12:22:44.105278030 +1200
+@@ -1,3 +1,2 @@
+ 1
+-2
+ 3
+)";
+    {
+        Patch::File file("diff.patch", std::ios_base::out);
+        file << patch;
+        file.close();
+    }
+
+    std::string to_patch = "a\nb\nc\n";
+    {
+        Patch::File file("1", std::ios_base::out);
+        file << to_patch;
+        file.close();
+    }
+
+    Process process(patch_path, { patch_path, "-i", "diff.patch", "-o", "-", "--force", nullptr });
+
+    EXPECT_EQ(process.stdout_data(), to_patch);
+    EXPECT_EQ(process.stderr_data(), R"(patching file - (read from 1)
+Hunk #1 FAILED at 1.
+1 out of 1 hunk FAILED -- saving rejects to file -.rej
+)");
+    EXPECT_EQ(process.return_code(), 1);
+    EXPECT_FILE_EQ("1", to_patch);
+    EXPECT_FILE_EQ("-.rej", patch);
+}
+
 PATCH_TEST(failed_patch_dry_run)
 {
     {