From 411f911b60135ae6992ea667b1e7eeb2512af7e6 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Sat, 15 Sep 2018 00:42:05 -0500
Subject: [PATCH] Bump sym file version and add a couple sanity checks.

Bumping the version forces regeneration of any sym files created by old ORCA/C versions with the bug that was just fixed.

A couple sanity checks are also introduced when reading sym files, including one that would have caught that bug.
---
 CCommon.pas |  1 +
 Header.pas  | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/CCommon.pas b/CCommon.pas
index c2954be..4aded5e 100644
--- a/CCommon.pas
+++ b/CCommon.pas
@@ -942,6 +942,7 @@ case errnum of                          {print the error}
    9 : msg := concat('Error writing ', objFile.theString.theString);
    10: msg := 'ORCA/C requires version 2.0 or later of the shell';
    11: msg := 'The program is too large to compile to memory -- use Compile to Disk';
+   12: msg := 'Invalid sym file detected. Re-run ORCA/C to proceed.';
    otherwise: begin
       msg := '';
       Error(57);
diff --git a/Header.pas b/Header.pas
index 19f93a0..f701038 100644
--- a/Header.pas
+++ b/Header.pas
@@ -18,7 +18,7 @@ uses CCommon, MM, Scanner, Symbol, CGI;
 {$segment 'SCANNER'}
 
 const
-   symFileVersion = 2;                  {version number of .sym file format}
+   symFileVersion = 3;                  {version number of .sym file format}
 
 var
    inhibitHeader: boolean;		{should .sym includes be blocked?}
@@ -1647,6 +1647,7 @@ var
             1: begin			{read a type displacement}
                tdisp := typeDispList;
                disp := ReadLong;
+               tp := nil;
                while tdisp <> nil do
         	  if tdisp^.saveDisp = disp then begin
                      tp := tdisp^.tPtr;
@@ -1654,6 +1655,11 @@ var
                      end {if}
         	  else 
                      tdisp := tdisp^.next;
+               if tp = nil then begin
+                  PurgeSymbols;
+                  DestroySymbolFile;
+                  TermError(12);
+                  end; {if}
                end; {case 1}
 
             2: tp := bytePtr;
@@ -1876,6 +1882,11 @@ if not ignoreSymbols then begin
             end; {while}
 	 DisposeTypeDispList;
 	 saveSource := false;
+         if ord4(symPtr) > ord4(symEndPtr) then begin
+            PurgeSymbols;
+            DestroySymbolFile;
+            TermError(12);
+            end; {if}
 	 end {if}
       else begin
 	 PurgeSymbols;			{no file found}