Do not fault! Tcl_Panic()! - improvements to handling Tcl_CreateChannel() args

1 files changed, 19 insertions, 0 deletions

diff --git a/generic/tclIO.c b/generic/tclIO.c
index 86ec27a..aabae0b 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -1548,6 +1548,25 @@ Tcl_CreateChannel(
      */
 
     assert(sizeof(Tcl_ChannelTypeVersion) == sizeof(Tcl_DriverBlockModeProc *));
+    assert(typePtr->typeName != NULL);
+    if (NULL == typePtr->closeProc) {
+	Tcl_Panic("channel type %s must define closeProc", typePtr->typeName);
+    }
+    if ((TCL_READABLE & mask) && (NULL == typePtr->inputProc)) {
+	Tcl_Panic("channel type %s must define inputProc when used for reader channel", typePtr->typeName);
+    }
+    if ((TCL_WRITABLE & mask) &&  (NULL == typePtr->outputProc)) {
+	Tcl_Panic("channel type %s must define outputProc when used for writer channel", typePtr->typeName);
+    }
+    if (NULL == typePtr->watchProc) {
+	Tcl_Panic("channel type %s must define watchProc", typePtr->typeName);
+    }
+    if (NULL == typePtr->getHandleProc) {
+	Tcl_Panic("channel type %s must define getHandleProc", typePtr->typeName);
+    }
+    if ((NULL!=typePtr->wideSeekProc) && (NULL == typePtr->seekProc)) {
+	Tcl_Panic("channel type %s must define seekProc if defining wideSeekProc", typePtr->typeName);
+    }
 
     /*
      * JH: We could subsequently memset these to 0 to avoid the numerous