fix(api): accept CRLF SKILL.md when importing skill zips (#41657)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Crazywoola <100913391+crazywoola@users.noreply.github.com>

api/services/agent/skill_package_service.py

@@ -105,12 +105,18 @@ class SkillPackageService:
             )
             skill_md_member = normalized_members[_SKILL_MD_NAME]
             self._validate_skill_md_size(skill_md_member)
-            skill_md_bytes = self._read_member_bytes_from_archive(archive, member_info=skill_md_member)
-            skill_md = self._decode_skill_md(skill_md_bytes)
+            raw_skill_md_bytes = self._read_member_bytes_from_archive(archive, member_info=skill_md_member)
+            skill_md = self._decode_skill_md(raw_skill_md_bytes)
+            skill_md_bytes = skill_md.encode("utf-8")
             normalized_archive_bytes = self._build_normalized_archive(
-                archive=archive, normalized_members=normalized_members
+                archive=archive,
+                normalized_members=normalized_members,
+                skill_md_bytes=skill_md_bytes,
+            )
+            normalized_size = sum(
+                len(skill_md_bytes) if path == _SKILL_MD_NAME else max(info.file_size, 0)
+                for path, info in normalized_members.items()
             )
-            normalized_size = sum(max(info.file_size, 0) for info in normalized_members.values())
 
         name, description = self._parse_skill_md(skill_md)
         try:
@@ -243,14 +249,17 @@ class SkillPackageService:
         *,
         archive: zipfile.ZipFile,
         normalized_members: dict[str, zipfile.ZipInfo],
+        skill_md_bytes: bytes,
     ) -> bytes:
         output = io.BytesIO()
         with zipfile.ZipFile(output, "w", compression=zipfile.ZIP_DEFLATED) as normalized_archive:
             for normalized_path in sorted(normalized_members):
-                normalized_archive.writestr(
-                    normalized_path,
-                    self._read_member_bytes_from_archive(archive, member_info=normalized_members[normalized_path]),
+                payload = (
+                    skill_md_bytes
+                    if normalized_path == _SKILL_MD_NAME
+                    else self._read_member_bytes_from_archive(archive, member_info=normalized_members[normalized_path])
                 )
+                normalized_archive.writestr(normalized_path, payload)
         return output.getvalue()
 
     @staticmethod
@@ -303,9 +312,11 @@ class SkillPackageService:
     @staticmethod
     def _decode_skill_md(raw: bytes) -> str:
         try:
-            return raw.decode("utf-8")
+            decoded = raw.decode("utf-8")
         except UnicodeDecodeError as exc:
             raise SkillPackageError("skill_md_not_utf8", "SKILL.md must be UTF-8 encoded", status_code=400) from exc
+        # Windows editors often save SKILL.md with CRLF; normalize before frontmatter parse.
+        return decoded.replace("\r\n", "\n").replace("\r", "\n")
 
     @classmethod
     def _parse_skill_md(cls, content: str) -> tuple[str, str]:

api/services/skill_management_service.py

@@ -114,7 +114,7 @@ _UNTITLED_SKILL_MD_BODY = """# Untitled skill
 
 Describe what this Skill does, when an Agent should use it, and any step-by-step instructions it must follow.
 """
-_FRONTMATTER_RE = re.compile(r"\A---\n(.*?)\n---\n?", re.DOTALL)
+_FRONTMATTER_RE = re.compile(r"\A---\r?\n(.*?)\r?\n---(?:\r?\n)?", re.DOTALL)
 _FILE_EXTENSION_RE = re.compile(r"\.[A-Za-z0-9][A-Za-z0-9._+-]*\Z")
 _SKILL_ASSISTANT_SYSTEM_PROMPT = """You are Dify's Skill Authoring assistant.
 
@@ -3614,7 +3614,13 @@ class SkillManagementService:
             )
 
     @staticmethod
-    def _parse_frontmatter(content: str) -> dict[str, Any]:
+    def _normalize_newlines(content: str) -> str:
+        """Normalize Windows/Mac newlines so SKILL.md frontmatter parsing is stable."""
+        return content.replace("\r\n", "\n").replace("\r", "\n")
+
+    @classmethod
+    def _parse_frontmatter(cls, content: str) -> dict[str, Any]:
+        content = cls._normalize_newlines(content)
         match = _FRONTMATTER_RE.match(content)
         if match is None:
             return {}
@@ -3639,9 +3645,9 @@ class SkillManagementService:
             )
         return payload
 
-    @staticmethod
-    def _frontmatter_field_line(content: str, field: str) -> int:
-        match = _FRONTMATTER_RE.match(content)
+    @classmethod
+    def _frontmatter_field_line(cls, content: str, field: str) -> int:
+        match = _FRONTMATTER_RE.match(cls._normalize_newlines(content))
         if match is None:
             return 2
         frontmatter_start_line = 2
@@ -3794,6 +3800,7 @@ class SkillManagementService:
                     if path == _SKILL_MD:
                         if text is None:
                             raise SkillManagementServiceError("invalid_skill_md", "SKILL.md must be UTF-8 text")
+                        text = self._normalize_newlines(text)
                         metadata = self._parse_frontmatter(text)
                         skill_md_content = text
                     if text is not None:

api/tests/unit_tests/services/agent/test_skill_package_service.py

@@ -51,6 +51,16 @@ def test_valid_skill_normalizes_manifest():
     assert len(manifest.hash) == 64
 
 
+def test_validate_and_normalize_accepts_crlf_skill_md():
+    crlf_skill_md = _SKILL_MD.replace("\n", "\r\n")
+    package = _normalize({"SKILL.md": crlf_skill_md.encode()})
+
+    assert package.manifest.name == "pdf-toolkit"
+    assert package.manifest.description == "Tools for working with PDF files."
+    assert b"\r" not in package.skill_md_bytes
+    assert package.skill_md_bytes.decode() == _SKILL_MD
+
+
 def test_name_and_description_are_required_in_frontmatter():
     with pytest.raises(SkillPackageError) as exc_info:
         _normalize({"SKILL.md": b"# heading-name\n\nbody"})

api/tests/unit_tests/services/test_skill_management_service.py

@@ -2664,6 +2664,38 @@ def test_import_skill_package_creates_draft_and_rejects_name_conflicts() -> None
     assert exc_info.value.code == "skill_name_conflict"
 
 
+def test_import_skill_package_accepts_crlf_skill_md() -> None:
+    """Windows CRLF SKILL.md must not blank out the frontmatter name on import."""
+    skill_md = (
+        "---\r\n"
+        "name: expense-sop\r\n"
+        "description: Expenses\r\n"
+        "metadata:\r\n"
+        "  display-name: Expense SOP\r\n"
+        "---\r\n"
+        "\r\n"
+        "# Expenses\r\n"
+    )
+    package = io.BytesIO()
+    with zipfile.ZipFile(package, "w") as archive:
+        archive.writestr("expense-sop/SKILL.md", skill_md.encode("utf-8"))
+        archive.writestr("expense-sop/references/policy.md", "Policy")
+
+    service = SkillManagementService(tool_file_manager=_FakeToolFileManager())
+    imported = service.import_skill(
+        tenant_id=TENANT,
+        user_id=USER,
+        payload=SkillImportPayload(content=package.getvalue(), filename="expense-sop.zip"),
+    )
+
+    assert imported["name"] == "expense-sop"
+    assert imported["display_name"] == "Expense SOP"
+    assert imported["description"] == "Expenses"
+    skill_md_file = next(item for item in imported["files"] if item["path"] == "SKILL.md")
+    assert "\r" not in skill_md_file["content"]
+    assert skill_md_file["content"].startswith("---\nname: expense-sop\n")
+
+
 def test_import_skill_package_strips_root_alongside_macos_metadata_folder() -> None:
     package = io.BytesIO()
     with zipfile.ZipFile(package, "w") as archive: