fixes #30604 - Cannot read properties of null (reading 'tagName')

[furcan]

TypeError: Cannot read properties of null (reading 'tagName') #30604

• Fixes TypeError: Cannot read properties of null (reading 'tagName') #30604

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
buildDuration	21.8s	22s	⚠️ +239ms
buildDurationCached	4.4s	4.7s	⚠️ +258ms
nodeModulesSize	293 MB	293 MB	⚠️ +245 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.692	3.796	⚠️ +0.1
/ avg req/sec	677.21	658.52	⚠️ -18.69
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.884	1.877	-0.01
/error-in-render avg req/sec	1327.02	1332.14	+5.12

Client Bundles (main, webpack, commons) Overall increase ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	28 kB	28 kB	⚠️ +14 B
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	71.9 kB	71.9 kB	⚠️ +14 B

Legacy Client Bundles (polyfills)

	vercel/next.js canary	furcan/next.js patch-1	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	furcan/next.js patch-1	Change
_app-HASH.js gzip	1.23 kB	1.23 kB	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	635 B	635 B	✓
image-HASH.js gzip	4.44 kB	4.44 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.87 kB	1.87 kB	✓
routerDirect..HASH.js gzip	321 B	321 B	✓
script-HASH.js gzip	383 B	383 B	✓
withRouter-HASH.js gzip	318 B	318 B	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	furcan/next.js patch-1	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes Overall increase ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
index.html gzip	522 B	522 B	✓
link.html gzip	534 B	535 B	⚠️ +1 B
withRouter.html gzip	516 B	516 B	✓
Overall change	1.57 kB	1.57 kB	⚠️ +1 B

Diffs

Diff for main-HASH.js

@@ -118,7 +118,14 @@
           i < headCount;
           i++, j = j.previousElementSibling
         ) {
-          if (j.tagName.toLowerCase() === type) {
+          var ref;
+          if (
+            (j === null || j === void 0
+              ? void 0
+              : (ref = j.tagName) === null || ref === void 0
+              ? void 0
+              : ref.toLowerCase()) === type
+          ) {
             oldTags.push(j);
           }
         }

Diff for index.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

Diff for link.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

Diff for withRouter.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

---

Default Build with SWC (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
buildDuration	24.3s	24.2s	-134ms
buildDurationCached	4.7s	4.6s	-56ms
nodeModulesSize	293 MB	293 MB	⚠️ +245 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	furcan/next.js patch-1	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.83	3.705	-0.12
/ avg req/sec	652.82	674.77	+21.95
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	2.09	1.924	-0.17
/error-in-render avg req/sec	1195.99	1299.49	+103.5

Client Bundles (main, webpack, commons) Overall increase ⚠️

	vercel/next.js canary	furcan/next.js patch-1	Change
450.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.3 kB	42.3 kB	✓
main-HASH.js gzip	28.2 kB	28.2 kB	⚠️ +9 B
webpack-HASH.js gzip	1.43 kB	1.43 kB	✓
Overall change	72.1 kB	72.1 kB	⚠️ +9 B

Legacy Client Bundles (polyfills)

	vercel/next.js canary	furcan/next.js patch-1	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	furcan/next.js patch-1	Change
_app-HASH.js gzip	1.22 kB	1.22 kB	✓
_error-HASH.js gzip	180 B	180 B	✓
amp-HASH.js gzip	305 B	305 B	✓
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.38 kB	2.38 kB	✓
head-HASH.js gzip	342 B	342 B	✓
hooks-HASH.js gzip	622 B	622 B	✓
image-HASH.js gzip	4.46 kB	4.46 kB	✓
index-HASH.js gzip	256 B	256 B	✓
link-HASH.js gzip	1.91 kB	1.91 kB	✓
routerDirect..HASH.js gzip	314 B	314 B	✓
script-HASH.js gzip	375 B	375 B	✓
withRouter-HASH.js gzip	309 B	309 B	✓
334f979574ae..6f4.css gzip	106 B	106 B	✓
Overall change	13.1 kB	13.1 kB	✓

Client Build Manifests

	vercel/next.js canary	furcan/next.js patch-1	Change
_buildManifest.js gzip	460 B	460 B	✓
Overall change	460 B	460 B	✓

Rendered Page Sizes Overall decrease ✓

	vercel/next.js canary	furcan/next.js patch-1	Change
index.html gzip	522 B	521 B	-1 B
link.html gzip	536 B	534 B	-2 B
withRouter.html gzip	516 B	515 B	-1 B
Overall change	1.57 kB	1.57 kB	-4 B

Diffs

Diff for main-HASH.js

@@ -118,7 +118,14 @@
           i < headCount;
           i++, j = j.previousElementSibling
         ) {
-          if (j.tagName.toLowerCase() === type) {
+          var ref;
+          if (
+            (j === null || j === void 0
+              ? void 0
+              : (ref = j.tagName) === null || ref === void 0
+              ? void 0
+              : ref.toLowerCase()) === type
+          ) {
             oldTags.push(j);
           }
         }

Diff for index.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

Diff for link.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

Diff for withRouter.html

@@ -19,7 +19,7 @@
       defer=""
     ></script>
     <script
-      src="/_next/static/chunks/main-ab67a6af98bf1f43.js"
+      src="/_next/static/chunks/main-022dee77aa48ff79.js"
       defer=""
     ></script>
     <script

Commit: a672d8f