Skip stale latest prebuilts in installers

install.ps1

@@ -100,6 +100,85 @@ function Release-LatestTagDownloadUrl {
     return $null
 }
 
+function Version-Parts($Value) {
+    [regex]::Matches($Value, "\d+") | ForEach-Object { [int64]$_.Value }
+}
+
+function Compare-DoshVersion($Left, $Right) {
+    $leftParts = @(Version-Parts $Left)
+    $rightParts = @(Version-Parts $Right)
+    $width = [Math]::Max($leftParts.Count, $rightParts.Count)
+    for ($i = 0; $i -lt $width; $i++) {
+        $l = if ($i -lt $leftParts.Count) { $leftParts[$i] } else { 0 }
+        $r = if ($i -lt $rightParts.Count) { $rightParts[$i] } else { 0 }
+        if ($l -lt $r) { return -1 }
+        if ($l -gt $r) { return 1 }
+    }
+    return 0
+}
+
+function Current-SourceVersion {
+    if (Test-Path "Cargo.toml") {
+        $raw = Get-Content "Cargo.toml" -Raw
+    } else {
+        $web = Repo-WebBase $Repo
+        if (-not $web) {
+            return $null
+        }
+        try {
+            $raw = (Invoke-WebRequest -UseBasicParsing -Uri "$web/raw/branch/main/Cargo.toml").Content
+        }
+        catch {
+            return $null
+        }
+    }
+    if ($raw -match '(?m)^version = "([^"]+)"') {
+        return $Matches[1]
+    }
+    return $null
+}
+
+function Latest-ReleaseTag {
+    $web = Repo-WebBase $Repo
+    if (-not $web) {
+        return $null
+    }
+    try {
+        $response = Invoke-WebRequest -UseBasicParsing -Uri "$web/releases/latest" -MaximumRedirection 5
+        $effective = $null
+        if ($response.BaseResponse.ResponseUri) {
+            $effective = $response.BaseResponse.ResponseUri.AbsoluteUri
+        } elseif ($response.BaseResponse.RequestMessage -and $response.BaseResponse.RequestMessage.RequestUri) {
+            $effective = $response.BaseResponse.RequestMessage.RequestUri.AbsoluteUri
+        }
+        $prefix = "$web/releases/tag/"
+        if ($effective -and $effective.StartsWith($prefix)) {
+            return $effective.Substring($prefix.Length)
+        }
+    }
+    catch {
+        return $null
+    }
+    return $null
+}
+
+function Latest-ReleaseIsStale {
+    if ($BinaryUrl -or $BinaryBase -or $BinaryVersion -ne "latest") {
+        return $false
+    }
+    $latest = Latest-ReleaseTag
+    $current = Current-SourceVersion
+    if (-not $latest -or -not $current) {
+        return $false
+    }
+    $latestVersion = $latest.TrimStart("v")
+    if ((Compare-DoshVersion $latestVersion $current) -lt 0) {
+        Write-Warning "latest release $latestVersion is older than source $current; skipping stale prebuilt"
+        return $true
+    }
+    return $false
+}
+
 function Verify-ArchiveChecksum($Url, $Archive) {
     $checksumPath = "$Archive.sha256"
     try {
@@ -160,6 +239,9 @@ $configDir = Join-Path $HOME ".config\dosh"
 New-Item -ItemType Directory -Force -Path $bindir, $configDir | Out-Null
 
 function Install-Prebuilt {
+    if (Latest-ReleaseIsStale) {
+        return $false
+    }
     $url = Release-LatestTagDownloadUrl
     if (-not $url) {
         $url = Release-DownloadUrl

install.sh

@@ -222,6 +222,73 @@ release_latest_tag_download_url() {
   esac
 }
 
+version_part() {
+  version="$1"
+  index="$2"
+  printf '%s\n' "$version" \
+    | sed 's/[^0-9][^0-9]*/ /g' \
+    | awk -v index="$index" '{ value=$index; if (value == "") value=0; print value }'
+}
+
+version_less_than() {
+  left="$1"
+  right="$2"
+  for index in 1 2 3 4 5 6 7 8; do
+    lpart="$(version_part "$left" "$index")"
+    rpart="$(version_part "$right" "$index")"
+    if [ "$lpart" -lt "$rpart" ]; then
+      return 0
+    fi
+    if [ "$lpart" -gt "$rpart" ]; then
+      return 1
+    fi
+  done
+  return 1
+}
+
+current_source_version() {
+  if [ -f Cargo.toml ]; then
+    sed -n 's/^version = "\(.*\)"/\1/p' Cargo.toml | sed -n '1p'
+    return 0
+  fi
+  [ -n "$repo" ] || return 1
+  web_base="$(repo_web_base "$repo")" || return 1
+  curl -fsSL "$web_base/raw/branch/main/Cargo.toml" 2>/dev/null \
+    | sed -n 's/^version = "\(.*\)"/\1/p' \
+    | sed -n '1p'
+}
+
+latest_release_tag() {
+  [ -n "$repo" ] || return 1
+  web_base="$(repo_web_base "$repo")" || return 1
+  latest_url="$(curl -fsSL -o /dev/null -w '%{url_effective}' "$web_base/releases/latest" 2>/dev/null || true)"
+  case "$latest_url" in
+    "$web_base"/releases/tag/*)
+      tag="${latest_url##"$web_base"/releases/tag/}"
+      [ -n "$tag" ] || return 1
+      printf '%s\n' "$tag"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+latest_release_is_stale() {
+  if [ -n "$binary_url" ] || [ -n "$binary_base" ] || [ "$binary_version" != "latest" ]; then
+    return 1
+  fi
+  latest="$(latest_release_tag || true)"
+  current="$(current_source_version || true)"
+  [ -n "$latest" ] && [ -n "$current" ] || return 1
+  latest="${latest#v}"
+  if version_less_than "$latest" "$current"; then
+    echo "latest release $latest is older than source $current; skipping stale prebuilt" >&2
+    return 0
+  fi
+  return 1
+}
+
 find_extracted_binary() {
   find "$1" -type f -name "$2" 2>/dev/null | sed -n '1p'
 }
@@ -312,6 +379,9 @@ verify_archive_version() {
 }
 
 try_install_prebuilt() {
+  if latest_release_is_stale; then
+    return 1
+  fi
   download_url="$(release_latest_tag_download_url || release_download_url)" || return 1
   tmpdir="$(mktemp -d)"
   archive="$tmpdir/$(release_artifact_name)"

tests/release_scripts.rs

@@ -19,6 +19,27 @@ fn release_scripts_skip_stale_artifacts_when_auto_discovering() {
     assert!(publish.contains("actual=\"$(artifact_version \"$artifact\" || true)\""));
 }
 
+#[test]
+fn installers_skip_stale_latest_release_prebuilts() {
+    let install = include_str!("../install.sh");
+    assert!(install.contains("latest_release_is_stale"));
+    assert!(install.contains("current_source_version"));
+    assert!(install.contains("latest release $latest is older than source $current"));
+    assert!(
+        install.contains("if latest_release_is_stale; then"),
+        "unix installer must skip stale latest before downloading a prebuilt"
+    );
+
+    let ps1 = include_str!("../install.ps1");
+    assert!(ps1.contains("Latest-ReleaseIsStale"));
+    assert!(ps1.contains("Current-SourceVersion"));
+    assert!(ps1.contains("latest release $latestVersion is older than source $current"));
+    assert!(
+        ps1.contains("if (Latest-ReleaseIsStale)"),
+        "windows installer must skip stale latest before downloading a prebuilt"
+    );
+}
+
 #[test]
 fn package_check_verifies_only_artifacts_it_builds() {
     let makefile = include_str!("../Makefile");