Capture-MclCache: read files MCL still has open, skip any it cannot

scripts/diagnostics/Capture-MclCache.ps1

@@ -74,13 +74,31 @@ $rows | Sort-Object Path | Export-Csv -LiteralPath (Join-Path $dest "tree.csv")
 $copied = 0
 $redacted = 0
 $skippedBig = New-Object System.Collections.Generic.List[string]
+$unreadable = New-Object System.Collections.Generic.List[string]
 foreach ($f in $all) {
     if ($textExt -notcontains $f.Extension.ToLower()) { continue }
     $rel = $f.FullName.Substring($Root.Length + 1)
     if ($f.Length -gt $maxCopy) { $skippedBig.Add("$rel ($($f.Length) bytes)"); continue }
     $target = Join-Path $filesDir $rel
     New-Item -ItemType Directory -Path (Split-Path $target -Parent) -Force | Out-Null
-    $bytes = [System.IO.File]::ReadAllBytes($f.FullName)
+    # Share mode lets this read the log MCL still has open.
+    try {
+        $fs = New-Object System.IO.FileStream($f.FullName, [System.IO.FileMode]::Open,
+            [System.IO.FileAccess]::Read, ([System.IO.FileShare]::ReadWrite -bor [System.IO.FileShare]::Delete))
+        try {
+            $bytes = New-Object byte[] $fs.Length
+            $read = 0
+            while ($read -lt $bytes.Length) {
+                $n = $fs.Read($bytes, $read, $bytes.Length - $read)
+                if ($n -le 0) { break }
+                $read += $n
+            }
+            if ($read -lt $bytes.Length) { $bytes = $bytes[0..($read - 1)] }
+        } finally { $fs.Dispose() }
+    } catch {
+        $unreadable.Add("$rel ($($_.Exception.InnerException.Message))")
+        continue
+    }
     $text = [System.Text.Encoding]::UTF8.GetString($bytes)
     if ($text -match $sasPattern) {
         $text = [regex]::Replace($text, $sasPattern, '${1}REDACTED')
@@ -116,6 +134,11 @@ foreach ($g in ($rows | Group-Object { ($_.Path -split '\\')[0..1] -join '\' } |
     $gb = [math]::Round((($g.Group | Measure-Object Length -Sum).Sum) / 1GB, 2)
     $sum.Add("  $($g.Name): $($g.Count) files, $gb GB")
 }
+if ($unreadable.Count) {
+    $sum.Add("")
+    $sum.Add("Text files that could not be read, not copied:")
+    foreach ($s in $unreadable) { $sum.Add("  $s") }
+}
 if ($skippedBig.Count) {
     $sum.Add("")
     $sum.Add("Text files over 5 MB, not copied:")
@@ -131,4 +154,7 @@ Write-Host "Captured $($all.Count) files ($copied text files copied)." -Foregrou
 if ($tags.Count -eq 0) {
     Write-Host "WARNING: no .tag file. MCL did not finish this run." -ForegroundColor Yellow
 }
+if ($unreadable.Count) {
+    Write-Host "$($unreadable.Count) file(s) could not be read; listed in summary.txt." -ForegroundColor Yellow
+}
 Write-Host "Send back: $zip"