WIP

Author: spoorcc

dfetch/commands/format_patch.py

@@ -32,7 +32,6 @@
 import dfetch.manifest.project
 import dfetch.project
 from dfetch.log import get_logger
-from dfetch.project.git import GitSubProject
 from dfetch.project.superproject import SuperProject
 from dfetch.util.util import catch_runtime_exceptions, in_directory
 from dfetch.vcs.patch import PatchAuthor, PatchInfo, add_prefix_to_patch
@@ -117,7 +116,6 @@ def __call__(self, args: argparse.Namespace) -> None:
                             path_prefix=re.split(r"\*", subproject.source, 1)[0].rstrip(
                                 "/"
                             ),
-                            is_git=isinstance(subproject, GitSubProject),
                         )
 
                         output_patch_file = output_dir_path / pathlib.Path(patch).name

dfetch/project/superproject.py

@@ -111,7 +111,11 @@ def get_username(self) -> str:
         elif SvnRepo(self.root_directory).is_svn():
             username = SvnRepo(self.root_directory).get_username()
 
-        username = username or getpass.getuser()
+        if not username:
+            try:
+                username = getpass.getuser()
+            except Exception:
+                username = ""
         if not username:
             try:
                 username = os.getlogin()

dfetch/vcs/patch.py

@@ -5,7 +5,7 @@
 import hashlib
 import stat
 from collections.abc import Sequence
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from pathlib import Path
 
 import patch_ng
@@ -211,7 +211,9 @@ class PatchInfo:
     total_patches: int = 1
     current_patch_idx: int = 1
     revision: str = ""
-    date: datetime.datetime = datetime.datetime.now(tz=datetime.timezone.utc)
+    date: datetime.datetime = field(
+        default_factory=lambda: datetime.datetime.now(tz=datetime.timezone.utc)
+    )
     description: str = ""
 
     def to_git_header(self) -> str:
@@ -235,50 +237,42 @@ def to_svn_header(self) -> str:
         return ""
 
 
-def add_prefix_to_patch(file_path: str, path_prefix: str, is_git: bool = True) -> str:
-    """Rewrite a patch to prefix file paths."""
+def add_prefix_to_patch(file_path: str, path_prefix: str) -> str:
+    """Add a prefix to all file paths in the given patch file."""
     patch = patch_ng.fromfile(file_path)
-
-    if not patch:
+    if not patch or not patch.items:
         return ""
 
-    out: list[bytes] = []
+    # make sure prefix is bytes
+    prefix = path_prefix.strip("/").encode()  # b"myprefix"
+    if prefix:
+        prefix += b"/"
 
     for file in patch.items:
-        # normalize prefix (no leading/trailing slash surprises)
-        prefix = path_prefix.strip("/").encode()
-        prefix = prefix + b"/" if prefix else b""
-
-        src = file.source
-        tgt = file.target
-
-        # strip a/ b/ if present
-        if src.startswith(b"a/"):
-            src = src[2:]
-        if tgt.startswith(b"b/"):
-            tgt = tgt[2:]
-
-        new_src = b"a/" + prefix + src
-        new_tgt = b"b/" + prefix + tgt
-
-        # diff header
-        out.append(b"")
-        if is_git:
-            out.append(b"diff --git " + new_src + b" " + new_tgt)
-        else:
-            out.append(b"Index: " + new_src)
-            out.append(b"=" * 67)
-        out.append(b"--- " + new_src)
-        out.append(b"+++ " + new_tgt)
 
-        for hunk in file.hunks:
-            out.append(
-                f"@@ -{hunk.startsrc},{hunk.linessrc} "
-                f"+{hunk.starttgt},{hunk.linestgt} @@".encode()
-            )
-            for line in hunk.text:
-                out.append(line.rstrip(b"\r\n"))
+        def rewrite_path(path: bytes) -> bytes:
+            if path == b"/dev/null":
+                return b"/dev/null"
+            return prefix + path
+
+        file.source = rewrite_path(file.source)
+        file.target = rewrite_path(file.target)
 
-        out.append(b"")  # blank line between files
+    return dump(patch)
 
-    return b"\n".join(out).decode("utf-8")
+
+def dump(patch_set: patch_ng.PatchSet) -> str:
+    """Dump a patch set to a string."""
+    output_lines: list[str] = []
+    for p in patch_set.items:
+        for headline in p.header:
+            output_lines.append(headline.rstrip(b"\r\n").decode("utf-8"))
+        output_lines.append("--- " + p.source.decode("utf-8"))
+        output_lines.append("+++ " + p.target.decode("utf-8"))
+        for h in p.hunks:
+            output_lines.append(
+                f"@@ -{h.startsrc},{h.linessrc} +{h.starttgt},{h.linestgt} @@"
+            )
+            for line in h.text:
+                output_lines.append(line.rstrip(b"\r\n").decode("utf-8"))
+    return "\n".join(output_lines)

features/format-patch-in-git.feature

@@ -5,6 +5,7 @@ Feature: Formatting a patch for git repositories
     applied to the original repository. This way the upstream repository can
     be kept up to date with local changes.
 
+    @wip
     Scenario: All patch files are formatted
         Given the manifest 'dfetch.yaml'
             """
@@ -22,6 +23,7 @@ Feature: Formatting a patch for git repositories
                   patch:
                     - 001-diff.patch
                     - 002-diff.patch
+                    - 003-new-file.patch
             """
         And the patch file '001-diff.patch'
             """
@@ -45,14 +47,24 @@ Feature: Formatting a patch for git repositories
             -A test repo for testing patch.
             +A test repo for testing formatting patches.
             """
+        And the patch file '003-new-file.patch'
+            """
+            diff --git a/NEWFILE.md b/NEWFILE.md
+            new file mode 100644
+            index 0000000..e69de29
+            --- /dev/null
+            +++ b/NEWFILE.md
+            @@ -0,0 +1 @@
+            +This is a new file.
+            """
         And all projects are updated
         When I run "dfetch format-patch ext/test-repo-tag --output-directory patches"
         Then the patch file 'patches/001-diff.patch' is generated
             """
             From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
             From: John Doe <john@dfetch.io>
             Date: Mon, 02 Feb 2026 20:57:35 +0000
-            Subject: [PATCH 1/2] Patch for ext/test-repo-tag
+            Subject: [PATCH 1/3] Patch for ext/test-repo-tag
 
             Patch for ext/test-repo-tag
 
@@ -70,7 +82,7 @@ Feature: Formatting a patch for git repositories
             From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
             From: John Doe <john@dfetch.io>
             Date: Mon, 02 Feb 2026 21:02:42 +0000
-            Subject: [PATCH 2/2] Patch for ext/test-repo-tag
+            Subject: [PATCH 2/3] Patch for ext/test-repo-tag
 
             Patch for ext/test-repo-tag
 
@@ -82,4 +94,20 @@ Feature: Formatting a patch for git repositories
             -A test repo for testing patch.
             +A test repo for testing formatting patches.
 
+            """
+        And the patch file 'patches/003-new-file.patch' is generated
+            """
+            From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+            From: John Doe <john@dfetch.io>
+            Date: Mon, 02 Feb 2026 21:02:42 +0000
+            Subject: [PATCH 3/3] Patch for ext/test-repo-tag
+
+            Patch for ext/test-repo-tag
+
+            diff --git a/NEWFILE.md b/NEWFILE.md
+            --- a/NEWFILE.md
+            +++ b/NEWFILE.md
+            @@ -0,0 +1 @@
+            +This is a new file.
+
             """

tests/test_patch.py

@@ -13,6 +13,7 @@
 from hypothesis import strategies as st
 
 from dfetch.vcs.patch import (
+    add_prefix_to_patch,
     apply_patch,
     create_git_patch_for_new_file,
     create_svn_patch_for_new_file,
@@ -337,3 +338,46 @@ def test_reverse_patch_small_random(original_lines, rng):
 
         restored = target_file.read_text()
         assert restored == original, "Reverse patch did not restore original!"
+
+
+def test_patch_prefix_new_file(tmp_path):
+    """Test adding prefix to new file."""
+    original_patch = "\n".join(
+        [
+            "diff --git a/test.txt b/test.txt",
+            "new file mode 100644",
+            "index 0000000..8029fa5",
+            "--- /dev/null",
+            "+++ test.txt",
+            "@@ -0,0 +1,3 @@",
+            "+Hello World",
+            "+",
+            "+Line above is empty",
+            "",
+        ]
+    )
+
+    original_patch_file = tmp_path / "original.patch"
+    original_patch_file.write_text(original_patch)
+
+    expected_patch = "\n".join(
+        [
+            "diff --git a/src/test.txt b/src/test.txt",
+            "new file mode 100644",
+            "index 0000000..8029fa5",
+            "--- /dev/null",
+            "+++ src/test.txt",
+            "@@ -0,0 +1,3 @@",
+            "+Hello World",
+            "+",
+            "+Line above is empty",
+            "",
+        ]
+    )
+
+    prefixed_patch = add_prefix_to_patch(
+        original_patch_file,
+        path_prefix="src",
+    )
+
+    assert prefixed_patch == expected_patch