Merge pull request #2891 from ehuss/divide-by-zero-heading-bug

ehuss · web-flow · commit a097fe623216 · 2025-10-21T00:52:17.000Z
Avoid divide-by-zero in heading nav computation
diff --git a/crates/mdbook-html/front-end/templates/toc.js.hbs b/crates/mdbook-html/front-end/templates/toc.js.hbs
@@ -127,7 +127,7 @@ window.customElements.define('mdbook-sidebar-scrollbox', MDBookSidebarScrollbox)
         // proportional to the difference in size.
         if (documentHeight < windowHeight * 2) {
             const maxPixelsBelow = documentHeight - windowHeight;
-            const t = 1 - pixelsBelow / maxPixelsBelow;
+            const t = 1 - pixelsBelow / Math.max(1, maxPixelsBelow);
             const clamp = Math.max(0, Math.min(1, t));
             adjustedBottomAdd *= clamp;
         }

Original file line number	Diff line number	Diff line change
`@@ -127,7 +127,7 @@ window.customElements.define('mdbook-sidebar-scrollbox', MDBookSidebarScrollbox)`
`127`	`127`	`// proportional to the difference in size.`
`128`	`128`	`if (documentHeight < windowHeight * 2) {`
`129`	`129`	`const maxPixelsBelow = documentHeight - windowHeight;`
`130`		`- const t = 1 - pixelsBelow / maxPixelsBelow;`
	`130`	`+ const t = 1 - pixelsBelow / Math.max(1, maxPixelsBelow);`
`131`	`131`	`const clamp = Math.max(0, Math.min(1, t));`
`132`	`132`	`adjustedBottomAdd *= clamp;`
`133`	`133`	`}`