diff options
Diffstat (limited to 'generic')
| -rw-r--r-- | generic/tclIO.c | 141 |
1 files changed, 87 insertions, 54 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index 1dc808a..183c372 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -10,7 +10,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclIO.c,v 1.16 1999/08/19 17:39:17 hobbs Exp $ + * RCS: @(#) $Id: tclIO.c,v 1.17 1999/12/01 02:45:02 hobbs Exp $ */ #include "tclInt.h" @@ -1664,10 +1664,17 @@ Tcl_UnstackChannel (interp, chan) * structure. */ - Tcl_DString ds; /* storage to copy option information */ - Channel top; /* Save area for current transformation */ - Channel* chanDownPtr = chanPtr->supercedes; - int interest; /* interest mask of transformation before destruct. */ + Tcl_DString dsTrans; /* storage to save option information */ + Tcl_DString dsBuf; /* storage to save option information */ + Channel top; /* Save area for current transformation */ + Channel* chanDownPtr = chanPtr->supercedes; + int interest; /* interest mask of transformation + * before destruct. */ + int saveInputEncodingFlags; /* Save area for encoding */ + int saveOutputEncodingFlags; /* related information */ + Tcl_EncodingState saveInputEncodingState; + Tcl_EncodingState saveOutputEncodingState; + Tcl_Encoding saveEncoding; /* * Event handling: Disallow the delivery of events from the @@ -1680,16 +1687,14 @@ Tcl_UnstackChannel (interp, chan) interest = chanPtr->interestMask; (chanPtr->typePtr->watchProc) (chanPtr->instanceData, 0); - /* - * Save the transformation, then restore the old channel from the - * first structure downstream. The overall effect is that - * transformation and underlying channel swapped places, and the - * transformation is cut loose from the stack. Without the latter - * a Tcl_Close on the transformation would be impossible, as that - * procedure will free the structure, making 'top' unusable. + /* 1. Swap the information in the top channel (the transformation) + * and the channel below, with some exceptions. This additionally + * cuts the top channel out of the chain. Without the latter + * a Tcl_Close on the transformation would be impossible, as that + * procedure will free the structure, making 'top' unusable. * - * Beware, same information must not take part in the swap, - * use correction code to ensure this. + * chanPtr -> top channel, transformation. + * chanDownPtr -> channel immediately below the transformation. */ memcpy ((void*) &top, (void*) chanPtr, sizeof (Channel)); @@ -1697,6 +1702,15 @@ Tcl_UnstackChannel (interp, chan) top.supercedes = (Channel*) NULL; memcpy ((void*) chanDownPtr, (void*) &top, sizeof (Channel)); + /* Now: + * chanPtr -> channel immediately below the transformation, now top + * chanDownPtr -> transformation, cut loose. + * + * Handle the exceptions mentioned above, i.e. move the information + * from the transformation into the new top, and reinitialize it to + * safe values in the transformation. + */ + chanPtr->refCount = chanDownPtr->refCount; chanPtr->closeCbPtr = chanDownPtr->closeCbPtr; chanPtr->chPtr = chanDownPtr->chPtr; @@ -1713,25 +1727,32 @@ Tcl_UnstackChannel (interp, chan) chanDownPtr->timer = (Tcl_TimerToken) NULL; chanDownPtr->csPtr = (CopyState*) NULL; - /* - * Now it is possible to wind down the transformation (in 'top'), - * especially to copy the current encoding and translation control - * information down. - */ - - /* - * Move the currently active encoding from the transformation - * to the now uncovered channel. We assume here that this - * channel uses 'encoding binary' (==> encoding == NULL, etc. - * This allows us to simply copy the pointers without having to - * think about refcounts and deallocation of the old encoding. + /* The now uncovered channel still has encoding and eol-translation + * deactivated, i.e. switched to 'binary'. *Don't* touch this until + * after the transformation is closed for good, as it may write + * information into it during that (-> flushing of data waiting in + * internal buffers!) and rely on these settings. Thanks to Matt + * Newman <matt@sensus.org> for finding this goof. + * + * But we also have to protect the state of the encoding from removal + * during the close. So we save it in some local variables. + * Additionally the current value of the options is lost after we + * close, we have to save them now. */ - chanPtr->encoding = chanDownPtr->encoding; - chanPtr->inputEncodingState = chanDownPtr->inputEncodingState; - chanPtr->inputEncodingFlags = chanDownPtr->inputEncodingFlags; - chanPtr->outputEncodingState = chanDownPtr->outputEncodingState; - chanPtr->outputEncodingFlags = chanDownPtr->outputEncodingFlags; + saveEncoding = chanDownPtr->encoding; + saveInputEncodingState = chanDownPtr->inputEncodingState; + saveInputEncodingFlags = chanDownPtr->inputEncodingFlags; + saveOutputEncodingState = chanDownPtr->outputEncodingState; + saveOutputEncodingFlags = chanDownPtr->outputEncodingFlags; + + Tcl_DStringInit (&dsTrans); + Tcl_GetChannelOption (interp, (Tcl_Channel) chanDownPtr, + "-translation", &dsTrans); + + Tcl_DStringInit (&dsBuf); + Tcl_GetChannelOption (interp, (Tcl_Channel) chanDownPtr, + "-buffering", &dsBuf); /* * Prevent the accidential removal of the encoding during @@ -1745,29 +1766,7 @@ Tcl_UnstackChannel (interp, chan) chanDownPtr->outputEncodingFlags = TCL_ENCODING_START; /* - * And don't forget to reenable the EOL-translation used by the - * transformation. Using a DString to do this *is* a bit awkward, - * but still the best way to handle the complexities here, like - * flag manipulation and event system. - */ - - Tcl_DStringInit (&ds); - Tcl_GetChannelOption (interp, (Tcl_Channel) chanDownPtr, - "-translation", &ds); - Tcl_SetChannelOption (interp, (Tcl_Channel) chanPtr, - "-translation", ds.string); - - Tcl_DStringSetLength (&ds, 0); - - Tcl_GetChannelOption (interp, (Tcl_Channel) chanDownPtr, - "-buffering", &ds); - Tcl_SetChannelOption (interp, (Tcl_Channel) chanPtr, - "-buffering", ds.string); - - Tcl_DStringFree (&ds); - - /* - * Now a little trick: Add the transformation structure to the + * A little trick: Add the transformation structure to the * per-thread list of existing channels (which it never were * part of so far), or Tcl_Close/FlushChannel will panic * ("damaged channel list"). @@ -1785,6 +1784,40 @@ Tcl_UnstackChannel (interp, chan) Tcl_Close (interp, (Tcl_Channel)chanDownPtr); /* + * Now it is possible to wind down the transformation (in 'top'), + * especially to copy the current encoding and translation control + * information down. + */ + + /* + * Move the currently active encoding from the save area + * to the now uncovered channel. We assume here that this + * channel uses 'encoding binary' (==> encoding == NULL, etc. + * This allows us to simply copy the pointers without having to + * think about refcounts and deallocation of the old encoding. + * + * And don't forget to reenable the EOL-translation used by the + * transformation. Using a DString to do this *is* a bit awkward, + * but still the best way to handle the complexities here, like + * flag manipulation and event system. + */ + + chanPtr->encoding = saveEncoding; + chanPtr->inputEncodingState = saveInputEncodingState; + chanPtr->inputEncodingFlags = saveInputEncodingFlags; + chanPtr->outputEncodingState = saveOutputEncodingState; + chanPtr->outputEncodingFlags = saveOutputEncodingFlags; + + Tcl_SetChannelOption (interp, (Tcl_Channel) chanPtr, + "-translation", dsTrans.string); + + Tcl_SetChannelOption (interp, (Tcl_Channel) chanPtr, + "-buffering", dsBuf.string); + + Tcl_DStringFree (&dsTrans); + Tcl_DStringFree (&dsBuf); + + /* * Event handling: If the information from the now destroyed * transformation shows that there was interest in some events * call the 'WatchProc' of the now uncovered channel to renew |