From 8a9a7584a027e9112442dad2c9b9ee09332a71a1 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@microsoft.com>
Date: Mon, 27 Apr 2015 11:23:00 -0700
Subject: [PATCH 1/2] #42 Azure remote debugging - breaking doesn't work We've
 started trying to read the source file when listing frames, but we weren't
 handling the case where we couldn't load the file.

---
 .../Product/Debugger/Debugger/PythonProcess.cs  | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/Python/Product/Debugger/Debugger/PythonProcess.cs b/Python/Product/Debugger/Debugger/PythonProcess.cs
index 5ce2d6cac0..3695ba49ef 100644
--- a/Python/Product/Debugger/Debugger/PythonProcess.cs
+++ b/Python/Product/Debugger/Debugger/PythonProcess.cs
@@ -506,16 +506,23 @@ public PythonProcess(PythonLanguageVersion languageVersion, string exe, string a
         internal PythonAst GetAst(string filename) {
             PythonAst ast;
             lock (_astCacheLock) {
-                _astCache.TryGetValue(filename, out ast);
+                if (_astCache.TryGetValue(filename, out ast)) {
+                    return ast;
+                }
             }
 
-            if (ast == null) {
+            try {
                 using (var source = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read)) {
                     ast = Parser.CreateParser(source, LanguageVersion).ParseFile();
-                    lock (_astCacheLock) {
-                        _astCache[filename] = ast;
-                    }
                 }
+            } catch (IOException) {
+            } catch (UnauthorizedAccessException) {
+            } catch (NotSupportedException) {
+            } catch (System.Security.SecurityException) {
+            }
+
+            lock (_astCacheLock) {
+                _astCache[filename] = ast;
             }
 
             return ast;

From c6dd077436a15fc46b975080f72d579bb3c1eab7 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@microsoft.com>
Date: Mon, 27 Apr 2015 11:55:30 -0700
Subject: [PATCH 2/2] Also catch argument exceptions when reading ASTs.

---
 Python/Product/Debugger/Debugger/PythonProcess.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Python/Product/Debugger/Debugger/PythonProcess.cs b/Python/Product/Debugger/Debugger/PythonProcess.cs
index 3695ba49ef..ad7cb7d06c 100644
--- a/Python/Product/Debugger/Debugger/PythonProcess.cs
+++ b/Python/Product/Debugger/Debugger/PythonProcess.cs
@@ -515,6 +515,7 @@ public PythonProcess(PythonLanguageVersion languageVersion, string exe, string a
                 using (var source = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read)) {
                     ast = Parser.CreateParser(source, LanguageVersion).ParseFile();
                 }
+            } catch (ArgumentException) {
             } catch (IOException) {
             } catch (UnauthorizedAccessException) {
             } catch (NotSupportedException) {