scripts-blender/addons/blender_svn/prefs.py

@@ -19,6 +19,12 @@ from .threaded.background_process import Processes
 class SVN_addon_preferences(AddonPreferences):
     bl_idname = __package__
 
+    is_svn_installed: BoolProperty(
+        name="Is SVN Installed",
+        description="Whether the `svn` command works at all in the user's command line. If not, user needs to install SVN",
+        default=False
+    )
+
     repositories: CollectionProperty(type=SVN_repository)
 
     def init_repo(self, context, repo_path: Path or str):

scripts-blender/addons/blender_svn/props.py

@@ -27,12 +27,14 @@ class SVN_scene_properties(PropertyGroup):
         description="Absolute directory path of the SVN repository's root in the file system",
     )
 
-    def get_repo(self, context):
+    def get_repo(self, context) -> Optional['SVN_repository']:
         """Return the current repository.
         Depending on preferences, this is either the repo the current .blend file is in, 
         or whatever repo is selected in the preferences UI.
         """
         prefs = get_addon_prefs(context)
+        if not prefs.is_svn_installed:
+            return
 
         if prefs.active_repo_mode == 'CURRENT_BLEND':
             return self.get_scene_repo(context)
@@ -40,15 +42,20 @@ class SVN_scene_properties(PropertyGroup):
             return prefs.active_repo
 
     def get_scene_repo(self, context) -> Optional['SVN_repository']:
+        """Return the repository of the current file, even if the add-on is 
+        configured to another repository.
+        """
+        prefs = get_addon_prefs(context)
+        if not prefs.is_svn_installed:
+            return
+
         if not self.svn_url or not self.svn_directory:
             return
 
-        prefs = get_addon_prefs(context)
         for repo in prefs.repositories:
             if (repo.url == self.svn_url) and (Path(repo.directory) == Path(self.svn_directory)):
                 return repo
 
-
 registry = [
     SVN_scene_properties,
 ]

scripts-blender/addons/blender_svn/threaded/execute_subprocess.py

@@ -4,7 +4,6 @@
 import subprocess
 from typing import List
 
-
 def get_credential_commands(context) -> List[str]:
     repo = context.scene.svn.get_repo(context)
     assert (repo.is_cred_entered), "No username or password entered for this repository. The UI shouldn't have allowed you to get into a state where you can press an SVN operation button without having your credentials entered, so this is a bug!"
@@ -29,6 +28,9 @@ def execute_svn_command(context, command: List[str], *, ignore_errors=False, pri
     SVN root.
     """
     repo = context.scene.svn.get_repo(context)
+    if "svn" not in command:
+        command.insert(0, "svn")
+
     if use_cred:
         command += get_credential_commands(context)
 
@@ -46,3 +48,7 @@ def execute_svn_command(context, command: List[str], *, ignore_errors=False, pri
                 print(f"Command returned error: {command}")
                 print(err_msg)
             raise error
+
+def check_svn_installed():
+    code, message = subprocess.getstatusoutput('svn')
+    return code != 127

scripts-blender/addons/blender_svn/threaded/svn_status.py

@@ -4,7 +4,7 @@
 from ..svn_info import get_svn_info
 from ..util import get_addon_prefs
 from .. import constants
-from .execute_subprocess import execute_svn_command
+from .execute_subprocess import execute_svn_command, check_svn_installed
 from .background_process import BackgroundProcess, Processes
 from bpy.types import Operator
 from bpy.props import StringProperty
@@ -64,11 +64,18 @@ def ensure_svn_of_current_file(_scene=None):
     """
 
     context = bpy.context
+    prefs = get_addon_prefs(context)
+    prefs.is_svn_installed = check_svn_installed()
+    if not prefs.is_svn_installed:
+        return
+
     scene_svn = context.scene.svn
 
-    prefs = get_addon_prefs(context)
     prefs.sync_repo_info_file()
 
+    if prefs.active_repo_idx == -1 and len(prefs.repositories) > 0:
+        prefs.active_repo_idx = 0
+
     repo = prefs.active_repo
     if repo and repo.is_cred_entered and repo.authenticated:
         status = Processes.get('Status')

scripts-blender/addons/blender_svn/ui/ui_file_list.py

@@ -149,8 +149,10 @@ class SVN_UL_file_list(UIList):
 
         row.prop(self, 'show_file_paths', text="",
                  toggle=True, icon="FILE_FOLDER")
-        row.prop(context.scene.svn.get_repo(context),
-                 'file_search_filter', text="")
+
+        repo = context.scene.svn.get_repo(context)
+        if repo:
+            row.prop(repo, 'file_search_filter', text="")
 
 
 def draw_process_info(context, layout):

scripts-blender/addons/blender_svn/ui/ui_log.py

@@ -90,6 +90,9 @@ class SVN_UL_log(UIList):
 
 def is_log_useful(context):
     repo = context.scene.svn.get_repo(context)
+    if not repo:
+        return False
+
     if len(repo.log) == 0 or len(repo.external_files) == 0:
         return False
     active_file = repo.active_file

scripts-blender/addons/blender_svn/ui/ui_prefs.py

@@ -99,12 +99,34 @@ class SVN_MT_add_repo(Menu):
 
 
 def draw_prefs(self, context):
+    if not self.is_svn_installed:
+        draw_prefs_no_svn(self, context)
+        return
+
     if self.checkout_mode:
         draw_prefs_checkout(self, context)
     else:
         draw_prefs_repos(self, context)
 
 
+def draw_prefs_no_svn(self, context):
+    terminal, url = "terminal", "https://subversion.apache.org/packages.html"
+    system = platform.system()
+    if system == "Windows":
+        terminal = "command line (cmd.exe)"
+        url = "https://subversion.apache.org/packages.html#windows"
+    elif system == "Darwin":
+        terminal = "Mac terminal"
+        url = "https://subversion.apache.org/packages.html#osx"
+
+    layout = self.layout
+    col = layout.column()
+    col.alert=True
+    col.label(text="Please ensure that Subversion (aka. SVN) is installed on your system.")
+    col.label(text=f"Typing `svn` into the {terminal} should yield a result.")
+    layout.operator("wm.url_open", icon='URL', text='Open Subversion Distribution Page').url=url
+
+
 def draw_prefs_checkout(self, context):
     def get_terminal_howto():
         msg_windows = "If you don't, cancel this operation and toggle it using Window->Toggle System Console."