added tests

src/absil/ilread.fs

@@ -1537,7 +1537,9 @@ let readStringHeapOption   ctxt idx = if idx = 0 then None else Some (readString
 let emptyByteArray: byte[] = [||]
 let readBlobHeapUncached ctxtH idx = 
     let ctxt = getHole ctxtH
-    if idx < 0 || idx >= ctxt.blobsStreamSize then emptyByteArray
+    // valid index lies in range [1..streamSize)
+    // NOTE: idx cannot be 0 - Blob\String heap has first empty element that is one byte 0
+    if idx <= 0 || idx >= ctxt.blobsStreamSize then emptyByteArray
     else seekReadBlob ctxt.is (ctxt.blobsStreamPhysicalLoc + idx) 
 let readBlobHeap        ctxt idx = ctxt.readBlobHeap idx 
 let readBlobHeapOption ctxt idx = if idx = 0 then None else Some (readBlobHeap ctxt idx) 

tests/fsharp/core/ilread/build.bat

@@ -0,0 +1,35 @@
+@if "%_echo%"=="" echo off
+
+setlocal
+REM Configure the sample, i.e. where to find the F# compiler and C# compiler.
+if EXIST build.ok DEL /f /q build.ok
+
+call %~d0%~p0..\..\..\config.bat
+@if ERRORLEVEL 1 goto Error
+
+if NOT "%FSC:NOTAVAIL=X%" == "%FSC%" ( 
+  REM Skipping test for FSI.EXE
+  goto Skip
+)
+
+"%FSC%" %fsc_flags% /r:Library.dll /out:test.exe test.fs
+@if ERRORLEVEL 1 goto Error
+
+"%PEVERIFY%" test.exe
+@if ERRORLEVEL 1 goto Error
+
+:Ok
+echo Built fsharp %~f0 ok.
+echo. > build.ok
+endlocal
+exit /b 0
+
+:Skip
+echo Skipped %~f0
+endlocal
+exit /b 0
+
+
+:Error
+endlocal
+exit /b %ERRORLEVEL%

tests/fsharp/core/ilread/run.bat

@@ -0,0 +1,22 @@
+@if "%_echo%"=="" echo off
+
+setlocal 
+dir build.ok > NUL ) || (
+  @echo 'build.ok' not found.
+  goto :ERROR
+)
+
+call %~d0%~p0..\..\..\config.bat
+
+%CLIX% .\test.exe
+if ERRORLEVEL 1 goto Error
+
+:Ok
+echo Ran fsharp %~f0 ok.
+endlocal
+exit /b 0
+
+:Error
+endlocal
+exit /b %ERRORLEVEL%
+

tests/fsharp/core/ilread/test.fs

@@ -0,0 +1,6 @@
+open Library
+
+let main _ =
+    let cls = Class1()
+    let len = cls.GetLength("123")
+    if len = 3 then 0 else 1

tests/test.lst

@@ -34,6 +34,7 @@ Core03		fsharp\core\innerpoly
 Core03		fsharp\core\int32
 Core03		fsharp\core\internalsvisible
 Core03		fsharp\core\interop
+Core03		fsharp\core\ilread
 Core03		fsharp\core\lazy
 Core03		fsharp\core\letrec
 Core03,Smoke		fsharp\core\libtest