From 3884d6e02e9e5a11bc1dd8d28392a7fba18498c9 Mon Sep 17 00:00:00 2001
From: Jehan Bruggeman <jehan@jetpack.ai>
Date: Wed, 5 Nov 2025 09:37:25 +0100
Subject: [PATCH] Restore previous behaviour of getting full doc size from
 Content-Range when available

---
 .../src/bindings/runtime_browser.ts           | 23 +++++++++++--------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/packages/duckdb-wasm/src/bindings/runtime_browser.ts b/packages/duckdb-wasm/src/bindings/runtime_browser.ts
index 34a1ed165..3b59d7b4f 100644
--- a/packages/duckdb-wasm/src/bindings/runtime_browser.ts
+++ b/packages/duckdb-wasm/src/bindings/runtime_browser.ts
@@ -296,14 +296,17 @@ export const BROWSER_RUNTIME: DuckDBRuntime & {
                             xhr.responseType = 'arraybuffer';
                             xhr.setRequestHeader('Range', `bytes=0-0`);
                             xhr.send(null);
-                            let actualContentLength = null;
-                            try { actualContentLength = xhr.getResponseHeader('Content-Length'); } catch (e: any) {console.warn(`Failed to get Content-Length on request`);}
-                            const contentRange = actualContentLength?.split('/')[1];
-                            const contentLength2 = actualContentLength;
+
+                            let contentLength = null;
+                            try { contentLength = xhr.getResponseHeader('Content-Length'); } catch (e: any) {console.warn(`Failed to get Content-Length on request`);}
+
+                            let contentRange = null;
+                            try { contentRange = xhr.getResponseHeader('Content-Range'); } catch (e: any) {console.warn(`Failed to get Content-Range on request`);}
+                            const fullLengthFromRange = contentRange?.split('/')[1] || null;
 
                             let presumedLength = null;
-                            if (contentRange !== undefined) {
-                                presumedLength = contentRange;
+                            if (fullLengthFromRange !== null) {
+                                presumedLength = fullLengthFromRange;
                             } else if (!file.reliableHeadRequests) {
                                 // Send a dummy HEAD request with range protocol
                                 //          -> good IFF status is 206 and contentLenght is present
@@ -327,8 +330,8 @@ export const BROWSER_RUNTIME: DuckDBRuntime & {
 
                             if (
                                 xhr.status == 206 &&
-                                contentLength2 !== null &&
-                                +contentLength2 == 1 &&
+                                fullLengthFromRange !== null &&
+                                +fullLengthFromRange == 1 &&
                                 presumedLength !== null
                             ) {
                                 const result = mod._malloc(3 * 8);
@@ -341,9 +344,9 @@ export const BROWSER_RUNTIME: DuckDBRuntime & {
                             }
                             if (
                                 xhr.status == 200 &&
-                                contentLength2 !== null &&
+                                fullLengthFromRange !== null &&
                                 contentLength !== null &&
-                                +contentLength2 == +contentLength
+                                +fullLengthFromRange == +contentLength
                             ) {
                                 console.warn(`fall back to full HTTP read for: ${file.dataUrl}`);
                                 const data = mod._malloc(xhr.response.byteLength);