diff --git a/templates/repo/editor/commit_form.tmpl b/templates/repo/editor/commit_form.tmpl
index f0f0f478268c6..94429452dd116 100644
--- a/templates/repo/editor/commit_form.tmpl
+++ b/templates/repo/editor/commit_form.tmpl
@@ -9,7 +9,7 @@
 			{{ctx.Locale.Tr "repo.editor.commit_changes"}}
 		{{- end}}</h3>
 		<div class="field">
-			<input name="commit_summary" placeholder="{{if .PageIsDelete}}{{ctx.Locale.Tr "repo.editor.delete" .TreePath}}{{else if .PageIsUpload}}{{ctx.Locale.Tr "repo.editor.upload_files_to_dir" .TreePath}}{{else if .IsNewFile}}{{ctx.Locale.Tr "repo.editor.add_tmpl"}}{{else if .PageIsPatch}}{{ctx.Locale.Tr "repo.editor.patch"}}{{else}}{{ctx.Locale.Tr "repo.editor.update" .TreePath}}{{end}}" value="{{.commit_summary}}" autofocus>
+			<input name="commit_summary" maxlength="100" placeholder="{{if .PageIsDelete}}{{ctx.Locale.Tr "repo.editor.delete" .TreePath}}{{else if .PageIsUpload}}{{ctx.Locale.Tr "repo.editor.upload_files_to_dir" .TreePath}}{{else if .IsNewFile}}{{ctx.Locale.Tr "repo.editor.add_tmpl"}}{{else if .PageIsPatch}}{{ctx.Locale.Tr "repo.editor.patch"}}{{else}}{{ctx.Locale.Tr "repo.editor.update" .TreePath}}{{end}}" value="{{.commit_summary}}" autofocus>
 		</div>
 		<div class="field">
 			<textarea name="commit_message" placeholder="{{ctx.Locale.Tr "repo.editor.commit_message_desc"}}" rows="5">{{.commit_message}}</textarea>
@@ -60,7 +60,7 @@
 			<div class="quick-pull-branch-name {{if not (eq .commit_choice "commit-to-new-branch")}}gt-hidden{{end}}">
 				<div class="new-branch-name-input field {{if .Err_NewBranchName}}error{{end}}">
 					{{svg "octicon-git-branch"}}
-					<input type="text" name="new_branch_name" value="{{.new_branch_name}}" class="input-contrast gt-mr-2 js-quick-pull-new-branch-name" placeholder="{{ctx.Locale.Tr "repo.editor.new_branch_name_desc"}}" {{if eq .commit_choice "commit-to-new-branch"}}required{{end}} title="{{ctx.Locale.Tr "repo.editor.new_branch_name"}}">
+					<input type="text" name="new_branch_name" maxlength="100" value="{{.new_branch_name}}" class="input-contrast gt-mr-2 js-quick-pull-new-branch-name" placeholder="{{ctx.Locale.Tr "repo.editor.new_branch_name_desc"}}" {{if eq .commit_choice "commit-to-new-branch"}}required{{end}} title="{{ctx.Locale.Tr "repo.editor.new_branch_name"}}">
 					<span class="text-muted js-quick-pull-normalization-info"></span>
 				</div>
 			</div>
diff --git a/templates/repo/editor/edit.tmpl b/templates/repo/editor/edit.tmpl
index cfc266731b144..a6dce81c08e9b 100644
--- a/templates/repo/editor/edit.tmpl
+++ b/templates/repo/editor/edit.tmpl
@@ -15,7 +15,7 @@
 					{{range $i, $v := .TreeNames}}
 						<div class="breadcrumb-divider">/</div>
 						{{if eq $i $l}}
-							<input id="file-name" value="{{$v}}" placeholder="{{ctx.Locale.Tr "repo.editor.name_your_file"}}" data-editorconfig="{{$.EditorconfigJson}}" required autofocus>
+							<input id="file-name" maxlength="500" value="{{$v}}" placeholder="{{ctx.Locale.Tr "repo.editor.name_your_file"}}" data-editorconfig="{{$.EditorconfigJson}}" required autofocus>
 							<span data-tooltip-content="{{ctx.Locale.Tr "repo.editor.filename_help"}}">{{svg "octicon-info"}}</span>
 						{{else}}
 							<span class="section"><a href="{{$.BranchLink}}/{{index $.TreePaths $i | PathEscapeSegments}}">{{$v}}</a></span>
diff --git a/templates/repo/editor/patch.tmpl b/templates/repo/editor/patch.tmpl
index 44c30bd5f90da..c9a78cc35fdf6 100644
--- a/templates/repo/editor/patch.tmpl
+++ b/templates/repo/editor/patch.tmpl
@@ -15,7 +15,7 @@
 					<a class="section" href="{{$.BranchLink}}">{{.BranchName}}</a>
 					<span>{{ctx.Locale.Tr "repo.editor.or"}} <a href="{{$.BranchLink}}">{{ctx.Locale.Tr "repo.editor.cancel_lower"}}</a></span>
 					<input type="hidden" id="tree_path" name="tree_path" value="" required>
-					<input id="file-name" type="hidden" value="diff.patch">
+					<input id="file-name" maxlength="500" type="hidden" value="diff.patch">
 				</div>
 			</div>
 			<div class="field">
diff --git a/templates/repo/editor/upload.tmpl b/templates/repo/editor/upload.tmpl
index d362a5602ac04..0a7c49dae3d16 100644
--- a/templates/repo/editor/upload.tmpl
+++ b/templates/repo/editor/upload.tmpl
@@ -13,7 +13,7 @@
 					{{range $i, $v := .TreeNames}}
 						<div class="breadcrumb-divider">/</div>
 						{{if eq $i $l}}
-							<input type="text" id="file-name" value="{{$v}}" placeholder="{{ctx.Locale.Tr "repo.editor.add_subdir"}}" autofocus>
+							<input type="text" id="file-name" maxlength="500" value="{{$v}}" placeholder="{{ctx.Locale.Tr "repo.editor.add_subdir"}}" autofocus>
 							<span data-tooltip-content="{{ctx.Locale.Tr "repo.editor.filename_help"}}">{{svg "octicon-info"}}</span>
 						{{else}}
 							<span class="section"><a href="{{$.BranchLink}}/{{index $.TreePaths $i | PathEscapeSegments}}">{{$v}}</a></span>
diff --git a/web_src/js/utils.js b/web_src/js/utils.js
index 3a2694335f0d0..ce0fb66343b13 100644
--- a/web_src/js/utils.js
+++ b/web_src/js/utils.js
@@ -2,13 +2,14 @@ import {encode, decode} from 'uint8-to-base64';
 
 // transform /path/to/file.ext to file.ext
 export function basename(path = '') {
-  return path ? path.replace(/^.*\//, '') : '';
+  const lastSlashIndex = path.lastIndexOf('/');
+  return lastSlashIndex < 0 ? path : path.substring(lastSlashIndex + 1);
 }
 
 // transform /path/to/file.ext to .ext
 export function extname(path = '') {
-  const [_, ext] = /.+(\.[^.]+)$/.exec(path) || [];
-  return ext || '';
+  const lastPointIndex = path.lastIndexOf('.');
+  return lastPointIndex < 0 ? '' : path.substring(lastPointIndex);
 }
 
 // test whether a variable is an object