Fix behavior of .INCLUDE within a macro or .REPEAT. In the original code

.INCLUDE was executed after expansion of the macro or .REPEAT - which was
wrong and caused all sorts of unexpected behavior. Related issues/PRs
are #231, #1473, #2159 and maybe others.

Note: After this change error messages for nested macro/.include statements
may be wrong. This is an unrelated bug that was always there and got exposed
by this fix. The bug needs to be addressed in a separate PR.

src/ca65/istack.c

@@ -156,3 +156,29 @@ void CheckInputStack (void)
         Error ("Open %s", IStack->Desc);
     }
 }
+
+
+
+InputStack RetrieveInputStack (void)
+/* Retrieve the current input stack. This will also clear it. Used when
+** including a file. The current input stack is stored together with the old
+** input file and restored when the file is closed.
+ */
+{
+    /* We do not touch the counter so input sources are counted across
+    ** includes.
+     */
+    InputStack S = IStack;
+    IStack = 0;
+    return S;
+}
+
+
+
+void RestoreInputStack (InputStack S)
+/* Restore an old input stack that was retrieved by RetrieveInputStack(). */
+{
+    CHECK (IStack == 0);
+    IStack = S;
+}
+

src/ca65/istack.h

@@ -38,6 +38,17 @@
 
 
 
+/*****************************************************************************/
+/*                                   Data                                    */
+/*****************************************************************************/
+
+
+
+/* Opaque pointer to an input stack */
+typedef void* InputStack;
+
+
+
 /*****************************************************************************/
 /*                                   Code                                    */
 /*****************************************************************************/
@@ -63,6 +74,15 @@ void CheckInputStack (void);
 ** stuff on the input stack.
 */
 
+InputStack RetrieveInputStack (void);
+/* Retrieve the current input stack. This will also clear it. Used when
+** including a file. The current input stack is stored together with the old
+** input file and restored when the file is closed.
+ */
+
+void RestoreInputStack (InputStack S);
+/* Restore an old input stack that was retrieved by RetrieveInputStack(). */
+
 
 
 /* End of istack.h */

src/ca65/scanner.c

@@ -113,6 +113,7 @@ struct CharSource {
     token_t                     Tok;    /* Last token */
     int                         C;      /* Last character */
     int                         SkipN;  /* For '\r\n' line endings, skip '\n\ if next */
+    InputStack                  IStack; /* Saved input stack */
     const CharSourceFunctions*  Func;   /* Pointer to function table */
     union {
         InputFile               File;   /* File data */
@@ -321,6 +322,9 @@ static void UseCharSource (CharSource* S)
     S->Tok      = CurTok.Tok;
     S->C        = C;
 
+    /* Remember the current input stack */
+    S->IStack   = RetrieveInputStack ();
+
     /* Use the new input source */
     S->Next     = Source;
     Source      = S;
@@ -347,7 +351,10 @@ static void DoneCharSource (void)
 
     /* Restore the old token */
     CurTok.Tok = Source->Tok;
-    C   = Source->C;
+    C = Source->C;
+
+    /* Restore the old input source */
+    RestoreInputStack (Source->IStack);
 
     /* Remember the last stacked input source */
     S = Source->Next;
@@ -1521,7 +1528,7 @@ CharAgain:
             /* In case of the main file, do not close it, but return EOF. */
             if (Source && Source->Next) {
                 DoneCharSource ();
-                goto Again;
+                goto Restart;
             } else {
                 CurTok.Tok = TOK_EOF;
             }