1 files changed, 53 insertions, 11 deletions

diff --git a/generic/tclEnsemble.c b/generic/tclEnsemble.c
index ad11785..473c4bb 100644
--- a/generic/tclEnsemble.c
+++ b/generic/tclEnsemble.c
@@ -2749,15 +2749,9 @@ TclCompileEnsemble(
     int ourResult = TCL_ERROR;
     unsigned numBytes;
     const char *word;
+    DefineLineInformation;
 
     Tcl_IncrRefCount(replaced);
-
-    /*
-     * This is where we return to if we are parsing multiple nested compiled
-     * ensembles. [info object] is such a beast.
-     */
-
-  checkNextWord:
     if (parsePtr->numWords < depth + 1) {
 	goto failed;
     }
@@ -2769,6 +2763,12 @@ TclCompileEnsemble(
 	goto failed;
     }
 
+    /*
+     * This is where we return to if we are parsing multiple nested compiled
+     * ensembles. [info object] is such a beast.
+     */
+
+  checkNextWord:
     word = tokenPtr[1].start;
     numBytes = tokenPtr[1].size;
 
@@ -2979,6 +2979,17 @@ TclCompileEnsemble(
 
     if (cmdPtr->compileProc == TclCompileEnsemble) {
 	tokenPtr = TokenAfter(tokenPtr);
+	if (parsePtr->numWords < depth + 1
+		|| tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+	    /*
+	     * Too hard because the user has done something unpleasant like
+	     * omitting the sub-ensemble's command name or used a non-constant
+	     * name for a sub-ensemble's command name; we respond by bailing
+	     * out completely (this is a rare case). [Bug 6d2f249a01]
+	     */
+
+	    goto cleanup;
+	}
 	ensemble = (Tcl_Command) cmdPtr;
 	goto checkNextWord;
     }
@@ -2998,6 +3009,23 @@ TclCompileEnsemble(
     }
 
     /*
+     * Throw out any line information generated by the failed compile attempt.
+     */
+
+    while (mapPtr->nuloc - 1 > eclIndex) {
+        mapPtr->nuloc--;
+        ckfree(mapPtr->loc[mapPtr->nuloc].line);
+        mapPtr->loc[mapPtr->nuloc].line = NULL;
+    }
+
+    /*
+     * Reset the index of next command.  Toss out any from failed nested
+     * partial compiles.
+     */
+
+    envPtr->numCommands = mapPtr->nuloc;
+
+    /*
      * Failed to do a full compile for some reason. Try to do a direct invoke
      * instead of going through the ensemble lookup process again.
      */
@@ -3009,8 +3037,24 @@ TclCompileEnsemble(
 		cmdPtr = oldCmdPtr;
 		depth--;
 	    }
-	    (void) Tcl_ListObjReplace(NULL, replaced, depth, 2, 0, NULL);
 	}
+	/*
+	 * The length of the "replaced" list must be depth-1.  Trim back
+	 * any extra elements that might have been appended by failing
+	 * pathways above.
+	 */
+	(void) Tcl_ListObjReplace(NULL, replaced, depth-1, INT_MAX, 0, NULL);
+
+	/*
+	 * TODO: Reconsider whether we ought to call CompileToInvokedCommand()
+	 * when depth==1.  In that case we are choosing to emit the
+	 * INST_INVOKE_REPLACE bytecode when there is in fact no replacing
+	 * to be done.  It would be equally functional and presumably more
+	 * performant to fall through to cleanup below, return TCL_ERROR,
+	 * and let the compiler harness emit the INST_INVOKE_STK
+	 * implementation for us.
+	 */
+
 	CompileToInvokedCommand(interp, parsePtr, replaced, cmdPtr, envPtr);
 	ourResult = TCL_OK;
     }
@@ -3179,9 +3223,7 @@ CompileToInvokedCommand(
      * Do the replacing dispatch.
      */
 
-    TclEmitInstInt4(INST_INVOKE_REPLACE, parsePtr->numWords, envPtr);
-    TclEmitInt1(numWords+1, envPtr);
-    TclAdjustStackDepth(-1, envPtr);	/* Correction to stack depth calcs. */
+    TclEmitInvoke(envPtr, INST_INVOKE_REPLACE, parsePtr->numWords,numWords+1);
 }
 
 /*