Merge PR #5594 into visible-batch stage

static/style.css

@@ -2912,10 +2912,14 @@
   .pwa-sidebar-edge-guard{display:none;}
 
   @media(min-width:901px){
-    html[data-workspace-panel="closed"] .rightpanel{width:0 !important;opacity:0;transform:translateX(14px);border-left-color:transparent;pointer-events:none;}
-    .layout.workspace-panel-collapsed .rightpanel{width:0 !important;opacity:0;transform:translateX(14px);border-left-color:transparent;pointer-events:none;}
+    html[data-workspace-panel="closed"] .rightpanel{width:0 !important;min-width:0 !important;opacity:0;transform:translateX(14px);border-left-color:transparent;pointer-events:none;}
+    .layout.workspace-panel-collapsed .rightpanel{width:0 !important;min-width:0 !important;opacity:0;transform:translateX(14px);border-left-color:transparent;pointer-events:none;}
     html[data-workspace-panel="closed"] .workspace-panel-edge-toggle{display:inline-flex;opacity:1;pointer-events:auto;transform:translateY(-50%);}
     html[data-workspace-panel="open"] .workspace-panel-edge-toggle{display:none;}
+    /* Keep the center readable before the rails hit their resize floor. */
+    .main{flex:1 1 420px;min-width:420px;}
+    .sidebar{flex-shrink:1;min-width:180px;}
+    .rightpanel{flex-shrink:1;min-width:180px;}
   }
 
   /* Sidebar collapse breakpoint matches `_isDesktopWidth()` (min-width:641px) so

tests/test_issue5545_three_panel_layout.py

@@ -0,0 +1,134 @@
+"""
+Issue #5545 three-panel desktop layout regression checks.
+
+These tests stay source-level so they can verify the declared CSS contract
+without needing a browser or rendered layout.
+"""
+
+import pathlib
+import re
+
+REPO = pathlib.Path(__file__).parent.parent
+CSS = (REPO / "static" / "style.css").read_text(encoding="utf-8")
+BOOT_JS = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
+
+
+def _media_blocks(kind):
+    pattern = re.compile(rf"@media\s*\(\s*{kind}\s*:\s*(\d+)px\s*\)\s*\{{")
+    blocks = []
+    for match in pattern.finditer(CSS):
+        width_px = int(match.group(1))
+        open_brace = match.end() - 1
+        depth = 0
+        for idx in range(open_brace, len(CSS)):
+            if CSS[idx] == "{":
+                depth += 1
+            elif CSS[idx] == "}":
+                depth -= 1
+                if depth == 0:
+                    blocks.append((width_px, CSS[open_brace + 1:idx]))
+                    break
+    return blocks
+
+
+def _normalize_css(css):
+    return re.sub(r"\s+", "", css)
+
+
+def _media_block(kind, width_px, needle):
+    normalized_needle = _normalize_css(needle)
+    for current_width, block in _media_blocks(kind):
+        if current_width == width_px and normalized_needle in _normalize_css(block):
+            return block
+    raise AssertionError(f"Missing @media({kind}:{width_px}px) block containing {needle!r}")
+
+
+def _strip_css_comments(css):
+    return re.sub(r"/\*.*?\*/", "", css, flags=re.DOTALL)
+
+
+def _rule_body(css, selector):
+    for match in re.finditer(r"([^{}]+)\{([^{}]*)\}", _strip_css_comments(css)):
+        selectors = {part.strip() for part in match.group(1).split(",")}
+        if selector in selectors:
+            return match.group(2)
+    raise AssertionError(f"Missing CSS rule for {selector}")
+
+
+def _declarations(rule_body):
+    declarations = {}
+    for item in rule_body.split(";"):
+        if ":" not in item:
+            continue
+        prop, value = item.split(":", 1)
+        declarations[prop.strip()] = re.sub(r"\s+", " ", value.strip())
+    return declarations
+
+
+def test_desktop_three_panel_contract_gives_main_readable_floor():
+    desktop = _media_block("min-width", 901, ".main{flex:1 1 420px;min-width:420px;}")
+    main = _declarations(_rule_body(desktop, ".main"))
+
+    assert main.get("flex") == "1 1 420px"
+    assert main.get("min-width") == "420px"
+
+
+def test_desktop_side_rails_can_shrink_to_resize_minima():
+    desktop = _media_block("min-width", 901, ".sidebar{flex-shrink:1;min-width:180px;}")
+    sidebar = _declarations(_rule_body(desktop, ".sidebar"))
+    rightpanel = _declarations(_rule_body(desktop, ".rightpanel"))
+    closed_rightpanel = _declarations(
+        _rule_body(desktop, 'html[data-workspace-panel="closed"] .rightpanel')
+    )
+    collapsed_rightpanel = _declarations(
+        _rule_body(desktop, ".layout.workspace-panel-collapsed .rightpanel")
+    )
+
+    assert re.search(r"\bSIDEBAR_MIN\s*=\s*180\b", BOOT_JS)
+    assert re.search(r"\bPANEL_MIN\s*=\s*180\b", BOOT_JS)
+    assert sidebar.get("flex-shrink") == "1"
+    assert sidebar.get("min-width") == "180px"
+    assert rightpanel.get("flex-shrink") == "1"
+    assert rightpanel.get("min-width") == "180px"
+    assert closed_rightpanel.get("width") == "0 !important"
+    assert closed_rightpanel.get("min-width") == "0 !important"
+    assert collapsed_rightpanel.get("width") == "0 !important"
+    assert collapsed_rightpanel.get("min-width") == "0 !important"
+
+
+def test_compact_breakpoint_900px_remains_hidden_right_panel_boundary():
+    assert "@media(max-width:900px)" in CSS or "@media (max-width: 900px)" in CSS
+
+    compact = _media_block("max-width", 900, ".rightpanel{display:none}")
+    rightpanel = _declarations(_rule_body(compact, ".rightpanel"))
+    workspace_toggle = _declarations(_rule_body(compact, ".workspace-toggle-btn"))
+    mobile_files = _declarations(_rule_body(compact, ".mobile-files-btn"))
+
+    assert rightpanel.get("display") == "none"
+    assert workspace_toggle.get("display") == "inline-flex!important"
+    assert mobile_files.get("display") == "inline-flex!important"
+
+
+def test_mobile_slide_over_breakpoint_640px_remains_intact():
+    assert "@media(max-width:640px)" in CSS or "@media (max-width: 640px)" in CSS
+
+    mobile = _media_block("max-width", 640, ".rightpanel.mobile-open")
+    rightpanel = _declarations(_rule_body(mobile, ".rightpanel"))
+    rightpanel_open = _declarations(_rule_body(mobile, ".rightpanel.mobile-open"))
+
+    assert rightpanel.get("display") == "flex!important"
+    assert rightpanel.get("position") == "fixed"
+    assert rightpanel.get("right") == "calc(-1 * var(--mobile-rightpanel-width))!important"
+    assert rightpanel.get("width") == "var(--mobile-rightpanel-width)!important"
+    assert rightpanel.get("box-shadow") == "none!important"
+    assert rightpanel_open.get("right") == "0!important"
+
+
+def test_no_unmatched_desktop_hide_breakpoint_above_900():
+    hidden_widths = []
+    for width_px, block in _media_blocks("max-width"):
+        if re.search(r"\.rightpanel\s*\{\s*display\s*:\s*none", block):
+            hidden_widths.append(width_px)
+
+    assert 900 in hidden_widths
+    assert all(width_px <= 900 for width_px in hidden_widths)