Sanitize product and view names before using them as paths

A product collection named "JNR 12 BICON " (trailing space, straight off
the STEP filename) made every render fail with "cannot save". Windows
strips trailing spaces and dots when it creates a directory entry, so
os.makedirs quietly produced "CC_11_JNR 12 BICON" while the render path
still pointed at "CC_11_JNR 12 BICON \...", and that directory genuinely
does not exist. The mismatch is invisible from Python: os.path.isdir
strips the same trailing space on the way in and reports the folder as
present.

Route the directory and file names through safe_name(), which trims
trailing spaces and dots, replaces characters Windows rejects, and
sidesteps the reserved device names. The label prefix already keeps each
product in its own folder, so names that clean up to the same text still
cannot collide.

Author: Danyals-code

multiview_product_renderer/__init__.py

@@ -675,6 +675,38 @@ def product_label(start_prefix, start_number, offset, per_letter):
     return f"{alpha_pair(base + bumps)}_{num:02d}"
 
 
+# Characters Windows refuses outright, plus the separators that would quietly
+# redirect a write into some other directory.
+BAD_PATH_CHARS = '<>:"/\\|?*'
+RESERVED_NAMES = (
+    {"CON", "PRN", "AUX", "NUL"}
+    | {f"COM{i}" for i in range(1, 10)}
+    | {f"LPT{i}" for i in range(1, 10)}
+)
+
+
+def safe_name(name, fallback="unnamed"):
+    """A collection or view name reduced to one usable path component.
+
+    These names are free text and usually arrive from a STEP filename, so they
+    carry whatever the CAD export happened to contain. A trailing space is the
+    one that bites: asked for 'BICON ', Windows quietly creates 'BICON', then
+    refuses to write 'BICON \\shot.png' because that directory really does not
+    exist, and the render dies on the first product with 'cannot save'. The
+    mismatch hides well, because os.path.isdir strips the same trailing space
+    on the way in and cheerfully agrees the folder is there.
+    """
+    cleaned = "".join(
+        "_" if c in BAD_PATH_CHARS or ord(c) < 32 else c for c in str(name)
+    )
+    # The name we ask for has to match the name the filesystem will hand back,
+    # or every later write into it misses.
+    cleaned = cleaned.strip().rstrip(" .")
+    if cleaned.split(".")[0].upper() in RESERVED_NAMES:
+        cleaned = f"_{cleaned}"
+    return cleaned or fallback
+
+
 STEPPER_OPERATORS = (
     "import_scene.occ_import_step",
     "import_scene.occ",
@@ -1607,13 +1639,13 @@ def execute(self, context):
                         lc.exclude = (other.name != pc.name)
 
                 label = product_label(s.start_prefix, s.start_number, i, s.products_per_letter)
-                product_dir = os.path.join(out_root, f"{label}_{pc.name}")
+                product_dir = os.path.join(out_root, safe_name(f"{label}_{pc.name}"))
                 os.makedirs(product_dir, exist_ok=True)
 
                 for cam in cameras:
                     scene.camera = cam
                     view_name = cam.name.replace("MV_Cam_", "")
-                    base = f"{label}_{pc.name}_{view_name}"
+                    base = safe_name(f"{label}_{pc.name}_{view_name}")
 
                     if mode == 'FULL':
                         _do_full_render(scene, os.path.join(product_dir, base))