diff --git a/push-to-gitea.ps1 b/push-to-gitea.ps1
index 013c27f..d11b74f 100644
--- a/push-to-gitea.ps1
+++ b/push-to-gitea.ps1
@@ -1,42 +1,88 @@
-# Pushes this folder into the Gitea repo created for it.
-# Run from PowerShell, inside the visitor-signin folder:
+# Pushes this folder to the Gitea repo.
+#
+# Run from PowerShell inside the visitor-signin folder:
 #     .\push-to-gitea.ps1
-# If Windows blocks it:  powershell -ExecutionPolicy Bypass -File .\push-to-gitea.ps1
+# If Windows blocks it:
+#     powershell -ExecutionPolicy Bypass -File .\push-to-gitea.ps1
 
-$ErrorActionPreference = 'Stop'
 $Remote = 'https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin.git'
 
-if (-not (Test-Path 'package.json')) {
-    Write-Error 'Run this from inside the visitor-signin folder.'
+# git reports failure through its exit code, not as a PowerShell error, so every
+# call has to be checked. Without this the script reports success after a
+# rejected push, which is exactly what it used to do.
+function Invoke-Git {
+    param([Parameter(ValueFromRemainingArguments = $true)][string[]]$Arguments)
+    & git @Arguments
+    return $LASTEXITCODE
+}
+
+function Fail($message) {
+    Write-Host ''
+    Write-Host $message -ForegroundColor Red
     exit 1
 }
 
+if (-not (Test-Path 'package.json')) { Fail 'Run this from inside the visitor-signin folder.' }
 if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
-    Write-Error 'Git is not installed or not on PATH. Install it from https://git-scm.com/download/win'
-    exit 1
+    Fail 'Git is not installed or not on PATH. Get it from https://git-scm.com/download/win'
 }
 
-# Keep line endings sane between Windows and the Ubuntu docker host.
+# Keeps line endings sane between Windows and the Ubuntu docker host.
 git config --global core.autocrlf input | Out-Null
 
 if (-not (Test-Path '.git')) {
-    git init -b main
-} else {
-    Write-Host 'This folder is already a git repo, adding a commit to it.'
+    Write-Host 'Setting up a new local repository...'
+    if ((Invoke-Git init -b main) -ne 0) { Fail 'git init failed.' }
 }
 
-git add .
-$message = 'Visitor sign in kiosk: multi-site, badge printing, WWCC expiry warnings, admin accounts with 2FA'
-git commit -m $message
-
-if (git remote | Select-String -Quiet '^origin$') {
+if ((git remote) -match '^origin$') {
     git remote set-url origin $Remote
 } else {
     git remote add origin $Remote
 }
 
-git push -u origin main
+# ---------------------------------------------------------------- commit
+
+git add -A
+$pending = git status --porcelain
+if ($pending) {
+    $message = Read-Host 'Describe this change (press enter for a dated default)'
+    if (-not $message) { $message = "Update $(Get-Date -Format 'yyyy-MM-dd HH:mm')" }
+    if ((Invoke-Git commit -m $message) -ne 0) { Fail 'git commit failed.' }
+    Write-Host 'Committed.' -ForegroundColor Green
+} else {
+    Write-Host 'No file changes to commit. Checking for anything unpushed...' -ForegroundColor Yellow
+}
+
+# ------------------------------------------------------- catch up, then push
+
+Write-Host 'Checking what is on the server...'
+if ((Invoke-Git fetch origin) -ne 0) {
+    Fail 'Could not reach Gitea. Check the network and your sign in details.'
+}
+
+if (git ls-remote --heads origin main) {
+    $behind = (git rev-list --count HEAD..origin/main 2>$null)
+    if ($behind -and [int]$behind -gt 0) {
+        Write-Host "The server has $behind commit(s) this folder does not. Replaying your work on top..."
+        if ((Invoke-Git pull --rebase origin main) -ne 0) {
+            Write-Host ''
+            Write-Host 'The two histories could not be joined automatically.' -ForegroundColor Red
+            Write-Host ''
+            Write-Host 'See what is on the server that you do not have:' -ForegroundColor Yellow
+            Write-Host '    git log --oneline HEAD..origin/main'
+            Write-Host ''
+            Write-Host 'If that is nothing you need, and this folder is the good copy:' -ForegroundColor Yellow
+            Write-Host '    git push --force-with-lease origin main'
+            exit 1
+        }
+    }
+}
+
+if ((Invoke-Git push -u origin main) -ne 0) {
+    Fail 'The push was rejected. Read the message above. Nothing was sent.'
+}
 
 Write-Host ''
-Write-Host 'Pushed. Repo: https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin' -ForegroundColor Green
-Write-Host 'Sign in with your Gitea username and password, or a token as the password.'
+Write-Host 'Pushed successfully.' -ForegroundColor Green
+Write-Host 'https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin'
diff --git a/push-to-gitea.sh b/push-to-gitea.sh
index 145283f..5aa3ed1 100644
--- a/push-to-gitea.sh
+++ b/push-to-gitea.sh
@@ -1,20 +1,58 @@
 #!/usr/bin/env bash
-# Pushes this folder into the (empty) Gitea repo created for it.
-# Run once from inside the extracted visitor-signin folder:  ./push-to-gitea.sh
-set -euo pipefail
+# Pushes this folder to the Gitea repo. Run from inside the visitor-signin folder.
+set -uo pipefail
 
 REMOTE="https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin.git"
 
-if [ ! -f package.json ]; then
-  echo "Run this from inside the visitor-signin folder." >&2
-  exit 1
+fail() { printf '\n%s\n' "$1" >&2; exit 1; }
+
+[ -f package.json ] || fail "Run this from inside the visitor-signin folder."
+command -v git >/dev/null || fail "Git is not installed."
+
+git config --global core.autocrlf input >/dev/null 2>&1 || true
+
+[ -d .git ] || git init -b main || fail "git init failed."
+
+if git remote | grep -qx origin; then
+  git remote set-url origin "$REMOTE"
+else
+  git remote add origin "$REMOTE"
 fi
 
-git init -b main
-git add .
-git commit -m "Visitor sign in kiosk: multi-site, badge printing, WWCC expiry warnings, admin accounts with 2FA"
-git remote add origin "$REMOTE" 2>/dev/null || git remote set-url origin "$REMOTE"
-git push -u origin main
+git add -A
+if [ -n "$(git status --porcelain)" ]; then
+  read -r -p "Describe this change (enter for a dated default): " MSG
+  [ -n "$MSG" ] || MSG="Update $(date '+%Y-%m-%d %H:%M')"
+  git commit -m "$MSG" || fail "git commit failed."
+  echo "Committed."
+else
+  echo "No file changes to commit. Checking for anything unpushed..."
+fi
+
+git fetch origin || fail "Could not reach Gitea."
+
+if git ls-remote --heads origin main | grep -q main; then
+  BEHIND=$(git rev-list --count HEAD..origin/main 2>/dev/null || echo 0)
+  if [ "$BEHIND" -gt 0 ]; then
+    echo "The server has $BEHIND commit(s) this folder does not. Replaying your work on top..."
+    if ! git pull --rebase origin main; then
+      cat >&2 <<'MSG'
+
+The two histories could not be joined automatically.
+
+See what is on the server that you do not have:
+    git log --oneline HEAD..origin/main
+
+If that is nothing you need, and this folder is the good copy:
+    git push --force-with-lease origin main
+MSG
+      exit 1
+    fi
+  fi
+fi
+
+git push -u origin main || fail "The push was rejected. Read the message above. Nothing was sent."
 
 echo
-echo "Pushed. Repo: https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin"
+echo "Pushed successfully."
+echo "https://gitea.hideawaygaming.com.au/jessikitty/visitor-signin"