Add Exception Handling Around More Recursive Extractor Calls (#599)

* Add Catch around Recursive Extractor calls

Was able to reproduce overflow exceptions thrown here causing end to execution, I think this is potentially the same root cause of issue #598's report of null streams causing a crash as well.

* Fix Capitalization

* Clamp GetLocation to end of file

Author: gfs

AppInspector.RulesEngine/RuleProcessor.cs

@@ -566,11 +566,11 @@ internal static string ExtractExcerpt(TextContainer text, Location start, Locati
 
         int startLineNumber =
             start.Line < 0 ? 0 : start.Line > text.LineEnds.Count ? text.LineEnds.Count - 1 : start.Line;
-        int endLineNUmber =
+        int endLineNumber =
             end.Line < 0 ? 0 : end.Line > text.LineEnds.Count ? text.LineEnds.Count - 1 : end.Line;
         // First we try to include the number of lines of context requested
         var excerptStartLine = Math.Max(0, startLineNumber - context);
-        var excerptEndLine = Math.Min(text.LineEnds.Count - 1, endLineNUmber + context);
+        var excerptEndLine = Math.Min(text.LineEnds.Count - 1, endLineNumber + context);
         var startIndex = text.LineStarts[excerptStartLine];
         var endIndex = text.LineEnds[excerptEndLine] + 1;
         // Maximum number of characters to capture on each side

AppInspector.RulesEngine/TextContainer.cs

@@ -449,12 +449,14 @@ public string GetLineContent(int line)
 
     /// <summary>
     ///     Returns location (Line, Column) for given index in text
+    ///     If the index is beyond the end of the file, clamps to the end
     /// </summary>
     /// <param name="index"> Position in text (line is one-indexed)</param>
     /// <returns> Location </returns>
     public Location GetLocation(int index)
     {
         for (var i = 1; i < LineEnds.Count; i++)
+        {
             if (LineEnds[i] >= index)
             {
                 return new Location
@@ -463,6 +465,17 @@ public Location GetLocation(int index)
                     Line = i
                 };
             }
+        }
+
+        // If the index is beyond the end of the file, clamp to the end of the file
+        if (index > LineEnds[^1])
+        {
+            return new Location()
+            {
+                Column = LineEnds[^1] - LineStarts[^1],
+                Line = LineEnds.Count
+            };
+        }
 
         return new Location();
     }

AppInspector/Commands/AnalyzeCommand.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
@@ -771,21 +772,38 @@ private IEnumerable<FileEntry> EnumerateFileEntries()
 
                 if (contents != null)
                 {
-                    if (_options.DisableCrawlArchives)
+                    IList<FileEntry> entriesToYield = new List<FileEntry>();
+                    try
                     {
-                        yield return new FileEntry(srcFile, contents);
+                        if (_options.DisableCrawlArchives)
+                        {
+                            entriesToYield.Add(new FileEntry(srcFile, contents));
+                        }
+                        else
+                        {
+                            // Use MemoryStreamCutoff = 1 to force using FileStream with DeleteOnClose for backing, and avoid memory exhaustion.
+                            ExtractorOptions opts = new()
+                            {
+                                Parallel = false, DenyFilters = _options.FilePathExclusions, MemoryStreamCutoff = 1
+                            };
+                            // This works if the contents contain any kind of file.
+                            // If the file is an archive this gets all the entries it contains.
+                            // If the file is not an archive, the stream is wrapped in a FileEntry container and yielded
+                            entriesToYield = extractor.Extract(srcFile, contents, opts).ToImmutableList();
+                        }
                     }
-                    else
+                    catch (Exception e)
                     {
-                        // Use MemoryStreamCutoff = 1 to force using FileStream with DeleteOnClose for backing, and avoid memory exhaustion.
-                        ExtractorOptions opts = new()
-                        {
-                            Parallel = false, DenyFilters = _options.FilePathExclusions, MemoryStreamCutoff = 1
-                        };
-                        // This works if the contents contain any kind of file.
-                        // If the file is an archive this gets all the entries it contains.
-                        // If the file is not an archive, the stream is wrapped in a FileEntry container and yielded
-                        foreach (var entry in extractor.Extract(srcFile, contents, opts)) yield return entry;
+                        _logger.LogDebug(
+                            "Failed to analyze file {Path}. {Type}:{Message}. ({StackTrace})",
+                            srcFile, e.GetType(), e.Message, e.StackTrace);
+                        _metaDataHelper?.Metadata.Files.Add(new FileRecord
+                            { FileName = srcFile, Status = ScanState.Error });
+                    }
+
+                    foreach (var entry in entriesToYield)
+                    {
+                        yield return entry;
                     }
                 }