Bug #3104: Compose table cache for faster X11 application starts. Part 1: Pointerless compose data structure, using indices instead of pointers, needed for mmap()ing data structure.

(cherry picked from 9354351fcb8baeaab85250d14409cfb4fa50f3e9 commit)

10 files changed, 219 insertions, 142 deletions

diff --git a/include/X11/Xlibint.h b/include/X11/Xlibint.h
index 8517f653..6b1e0c91 100644
--- a/include/X11/Xlibint.h
+++ b/include/X11/Xlibint.h
@@ -1255,6 +1255,12 @@ extern int _XOpenFile(
     int			/* flags */
 );
 
+extern int _XOpenFileMode(
+    _Xconst char*	/* path */,
+    int			/* flags */,
+    mode_t              /* mode */
+);
+
 extern void* _XFopenFile(
     _Xconst char*	/* path */,
     _Xconst char*	/* mode */
@@ -1265,6 +1271,7 @@ extern int _XAccessFile(
 );
 #else
 #define _XOpenFile(path,flags) open(path,flags)
+#define _XOpenFileMode(path,flags,mode) open(path,flags,mode)
 #define _XFopenFile(path,mode) fopen(path,mode)
 #endif
 
diff --git a/modules/im/ximcp/imLcFlt.c b/modules/im/ximcp/imLcFlt.c
index 1ca19df8..3b8f69e7 100644
--- a/modules/im/ximcp/imLcFlt.c
+++ b/modules/im/ximcp/imLcFlt.c
@@ -49,7 +49,8 @@ _XimLocalFilter(d, w, ev, client_data)
     Xic		 ic = (Xic)client_data;
     KeySym	 keysym;
     static char	 buf[256];
-    DefTree	*p;
+    DefTree	*b = ic->private.local.base.tree;
+    DTIndex	 t;
 
     if(ev->xkey.keycode == 0)
 	return (False);
@@ -74,7 +75,7 @@ _XimLocalFilter(d, w, ev, client_data)
 		if(ic->private.local.brl_committing) {
 		    ic->private.local.brl_committed =
 			ic->private.local.brl_committing;
-		    ic->private.local.composed = NULL;
+		    ic->private.local.composed = 0;
 		    ev->type = KeyPress;
 		    ev->xkey.keycode = 0;
 		    _XPutBackEvent(d, ev);
@@ -85,22 +86,21 @@ _XimLocalFilter(d, w, ev, client_data)
     }
 
     if(   (ev->type != KeyPress)
-       || (((Xim)ic->core.im)->private.local.top == (DefTree *)NULL) )
+       || (((Xim)ic->core.im)->private.local.top == 0 ) )
 	return(False);
 
-    for(p = ic->private.local.context; p; p = p->next) {
-	if(((ev->xkey.state & p->modifier_mask) == p->modifier) &&
-	    (keysym == p->keysym)) {
+    for(t = ic->private.local.context; t; t = b[t].next) {
+	if(((ev->xkey.state & b[t].modifier_mask) == b[t].modifier) &&
+	   (keysym == b[t].keysym))
 	    break;
-	}
     }
 
-    if(p) { /* Matched */
-	if(p->succession) { /* Intermediate */
-	    ic->private.local.context = p->succession;
+    if(t) { /* Matched */
+	if(b[t].succession) { /* Intermediate */
+	    ic->private.local.context = b[t].succession;
 	    return(True);
 	} else { /* Terminate (reached to leaf) */
-	    ic->private.local.composed = p;
+	    ic->private.local.composed = t;
 	    ic->private.local.brl_committed = 0;
 	    /* return back to client KeyPressEvent keycode == 0 */
 	    ev->xkey.keycode = 0;
diff --git a/modules/im/ximcp/imLcIc.c b/modules/im/ximcp/imLcIc.c
index ddf7c69e..fd6a4e1f 100644
--- a/modules/im/ximcp/imLcIc.c
+++ b/modules/im/ximcp/imLcIc.c
@@ -97,7 +97,7 @@ _XimLocalReset(
     XIC	 xic)
 {
     Xic	 ic = (Xic)xic;
-    ic->private.local.composed       = (DefTree *)NULL;
+    ic->private.local.composed       = 0;
     ic->private.local.context        = ((Xim)ic->core.im)->private.local.top;
     ic->private.local.brl_pressed    = 0;
     ic->private.local.brl_committing = 0;
@@ -152,8 +152,9 @@ _XimLocalCreateIC(
 
     ic->methods = &Local_ic_methods;
     ic->core.im = im;
+    ic->private.local.base           = ((Xim)im)->private.local.base;
     ic->private.local.context        = ((Xim)im)->private.local.top;
-    ic->private.local.composed       = (DefTree *)NULL;
+    ic->private.local.composed       = 0;
     ic->private.local.brl_pressed    = 0;
     ic->private.local.brl_committing = 0;
     ic->private.local.brl_committed  = 0;
diff --git a/modules/im/ximcp/imLcIm.c b/modules/im/ximcp/imLcIm.c
index 675b4822..37271ae4 100644
--- a/modules/im/ximcp/imLcIm.c
+++ b/modules/im/ximcp/imLcIm.c
@@ -78,23 +78,29 @@ _XimCheckIfLocalProcessing(im)
 
 Private void
 XimFreeDefaultTree(
-    DefTree *top)
+    DefTreeBase *b)
 {
-    if (!top) return;
-    if (top->succession) XimFreeDefaultTree(top->succession);
-    if (top->next) XimFreeDefaultTree(top->next);
-    if (top->mb) Xfree(top->mb);
-    if (top->wc) Xfree(top->wc);
-    if (top->utf8) Xfree(top->utf8);
-    Xfree(top);
+    if (!b) return;
+    if (b->tree)  Xfree (b->tree);
+    if (b->mb)    Xfree (b->mb);
+    if (b->wc)    Xfree (b->wc);
+    if (b->utf8)  Xfree (b->utf8);
+    b->tree = NULL;
+    b->mb   = NULL;
+    b->wc   = NULL;
+    b->utf8 = NULL;
+    b->treeused = b->treesize = 0;
+    b->mbused   = b->mbsize   = 0;
+    b->wcused   = b->wcsize   = 0;
+    b->utf8used = b->utf8size = 0;
 }
 
 Public void
 _XimLocalIMFree(
     Xim		im)
 {
-    XimFreeDefaultTree(im->private.local.top);
-    im->private.local.top = NULL;
+    XimFreeDefaultTree(&im->private.local.base);
+    im->private.local.top = 0;
 
     if(im->core.im_resources) {
 	Xfree(im->core.im_resources);
@@ -327,6 +333,11 @@ _XimLocalOpenIM(
 	goto Open_Error;
     private->ucstoutf8_conv = conv;
 
+    private->base.treeused = 1;
+    private->base.mbused   = 1;
+    private->base.wcused   = 1;
+    private->base.utf8used = 1;
+
     _XimCreateDefaultTree(im);
 
     im->methods = &Xim_im_local_methods;
diff --git a/modules/im/ximcp/imLcLkup.c b/modules/im/ximcp/imLcLkup.c
index f99cd831..b6a6ff60 100644
--- a/modules/im/ximcp/imLcLkup.c
+++ b/modules/im/ximcp/imLcLkup.c
@@ -56,13 +56,15 @@ _XimLocalMbLookupString(xic, ev, buffer, bytes, keysym, status)
 {
     Xic		 ic = (Xic)xic;
     int		 ret;
+    DefTree	*b  = ic->private.local.base.tree;
+    char	*mb = ic->private.local.base.mb;
 
     if(ev->type != KeyPress) {
 	if(status) *status = XLookupNone;
 	return(0);
     }
     if(ev->keycode == 0 && 
-	   (  (ic->private.local.composed != NULL)
+	   (  (ic->private.local.composed != 0)
 	    ||(ic->private.local.brl_committed != 0))) {
 	if (ic->private.local.brl_committed != 0) { /* Braille Event */
 	    unsigned char pattern = ic->private.local.brl_committed;
@@ -79,13 +81,13 @@ _XimLocalMbLookupString(xic, ev, buffer, bytes, keysym, status)
 		if(status) *status = XLookupChars;
 	    memcpy(buffer, mb, ret);
 	} else { /* Composed Event */
-	    ret = strlen(ic->private.local.composed->mb);
+	    ret = strlen(&mb[b[ic->private.local.composed].mb]);
 	    if(ret > bytes) {
 		if(status) *status = XBufferOverflow;
 		return(ret);
 	    }
-	    memcpy(buffer, ic->private.local.composed->mb, ret);
-	    if(keysym) *keysym = ic->private.local.composed->ks;
+	    memcpy(buffer, &mb[b[ic->private.local.composed].mb], ret);
+	    if(keysym) *keysym = b[ic->private.local.composed].ks;
 	    if (ret > 0) {
 		if (keysym && *keysym != NoSymbol) {
 		    if(status) *status = XLookupBoth;
@@ -133,6 +135,8 @@ _XimLocalWcLookupString(xic, ev, buffer, wlen, keysym, status)
 {
     Xic		 ic = (Xic)xic;
     int		 ret;
+    DefTree	*b  = ic->private.local.base.tree;
+    wchar_t	*wc = ic->private.local.base.wc;
 
     if(ev->type != KeyPress) {
 	if(status) *status = XLookupNone;
@@ -153,14 +157,14 @@ _XimLocalWcLookupString(xic, ev, buffer, wlen, keysym, status)
 	    } else
 		if(status) *status = XLookupChars;
 	} else { /* Composed Event */
-	    ret = _Xwcslen(ic->private.local.composed->wc);
+	    ret = _Xwcslen(&wc[b[ic->private.local.composed].wc]);
 	    if(ret > wlen) {
 		if(status) *status = XBufferOverflow;
 		return (ret);
 	    }
-	    memcpy((char *)buffer, (char *)ic->private.local.composed->wc,
+	    memcpy((char *)buffer, (char *)&wc[b[ic->private.local.composed].wc],
 		   ret * sizeof(wchar_t));
-	    if(keysym) *keysym = ic->private.local.composed->ks;
+	    if(keysym) *keysym = b[ic->private.local.composed].ks;
 	    if (ret > 0) {
 		if (keysym && *keysym != NoSymbol) {
 		    if(status) *status = XLookupBoth;
@@ -208,6 +212,8 @@ _XimLocalUtf8LookupString(xic, ev, buffer, bytes, keysym, status)
 {
     Xic		 ic = (Xic)xic;
     int		 ret;
+    DefTree	*b    = ic->private.local.base.tree;
+    char	*utf8 = ic->private.local.base.utf8;
 
     if(ev->type != KeyPress) {
 	if(status) *status = XLookupNone;
@@ -225,13 +231,13 @@ _XimLocalUtf8LookupString(xic, ev, buffer, bytes, keysym, status)
 	    buffer[1] = 0x80 | ((BRL_UC_ROW >> 8) & 0x30) | (pattern >> 6);
 	    buffer[2] = 0x80 | (pattern & 0x3f);
 	} else { /* Composed Event */
-	    ret = strlen(ic->private.local.composed->utf8);
+	    ret = strlen(&utf8[b[ic->private.local.composed].utf8]);
 	    if(ret > bytes) {
 		if(status) *status = XBufferOverflow;
 		return (ret);
 	    }
-	    memcpy(buffer, ic->private.local.composed->utf8, ret);
-	    if(keysym) *keysym = ic->private.local.composed->ks;
+	    memcpy(buffer, &utf8[b[ic->private.local.composed].utf8], ret);
+	    if(keysym) *keysym = b[ic->private.local.composed].ks;
 	    if (ret > 0) {
 		if (keysym && *keysym != NoSymbol) {
 		    if(status) *status = XLookupBoth;
diff --git a/modules/im/ximcp/imLcPrs.c b/modules/im/ximcp/imLcPrs.c
index fbad5a22..18147e9f 100644
--- a/modules/im/ximcp/imLcPrs.c
+++ b/modules/im/ximcp/imLcPrs.c
@@ -422,11 +422,13 @@ parseline(
     char* tokenbuf)
 {
     int token;
-    unsigned modifier_mask;
-    unsigned modifier;
-    unsigned tmp;
+    DTModifier modifier_mask;
+    DTModifier modifier;
+    DTModifier tmp;
     KeySym keysym = NoSymbol;
-    DefTree **top = &im->private.local.top;
+    DTIndex *top = &im->private.local.top;
+    DefTreeBase *b   = &im->private.local.base;
+    DTIndex t;
     DefTree *p = NULL;
     Bool exclam, tilde;
     KeySym rhs_keysym = 0;
@@ -438,8 +440,8 @@ parseline(
     char local_utf8_buf[LOCAL_UTF8_BUFSIZE], *rhs_string_utf8;
 
     struct DefBuffer {
-	unsigned modifier_mask;
-	unsigned modifier;
+	DTModifier modifier_mask;
+	DTModifier modifier;
 	KeySym keysym;
     };
 
@@ -536,20 +538,24 @@ parseline(
 
     token = nexttoken(fp, tokenbuf, &lastch);
     if (token == STRING) {
-	if( (rhs_string_mb = Xmalloc(strlen(tokenbuf) + 1)) == NULL )
-	    goto error;
+	l = strlen(tokenbuf) + 1;
+	while (b->mbused + l > b->mbsize) {
+	    b->mbsize = b->mbsize ? b->mbsize * 1.5 : 1024;
+	    if (! (b->mb = Xrealloc (b->mb, b->mbsize)) )
+		goto error;
+	}
+	rhs_string_mb = &b->mb[b->mbused];
+	b->mbused    += l;
 	strcpy(rhs_string_mb, tokenbuf);
 	token = nexttoken(fp, tokenbuf, &lastch);
 	if (token == KEY) {
 	    rhs_keysym = XStringToKeysym(tokenbuf);
 	    if (rhs_keysym == NoSymbol) {
-		Xfree(rhs_string_mb);
 		goto error;
 	    }
 	    token = nexttoken(fp, tokenbuf, &lastch);
 	}
 	if (token != ENDOFLINE && token != ENDOFFILE) {
-	    Xfree(rhs_string_mb);
 	    goto error;
 	}
     } else if (token == KEY) {
@@ -563,14 +569,13 @@ parseline(
 	}
 
         l = get_mb_string(im, local_mb_buf, rhs_keysym);
-        if (l == 0) {
-            rhs_string_mb = Xmalloc(1);
-	} else {
-            rhs_string_mb = Xmalloc(l + 1);
-        }
-	if( rhs_string_mb == NULL ) {
-	    goto error;
+	while (b->mbused + l + 1 > b->mbsize) {
+	    b->mbsize = b->mbsize ? b->mbsize * 1.5 : 1024;
+	    if (! (b->mb = Xrealloc (b->mb, b->mbsize)) )
+		goto error;
 	}
+	rhs_string_mb = &b->mb[b->mbused];
+	b->mbused    += l + 1;
         memcpy(rhs_string_mb, local_mb_buf, l);
 	rhs_string_mb[l] = '\0';
     } else {
@@ -581,62 +586,70 @@ parseline(
     if (l == LOCAL_WC_BUFSIZE - 1) {
 	local_wc_buf[l] = (wchar_t)'\0';
     }
-    if( (rhs_string_wc = (wchar_t *)Xmalloc((l + 1) * sizeof(wchar_t))) == NULL ) {
-	Xfree( rhs_string_mb );
-	return( 0 );
+    while (b->wcused + l + 1 > b->wcsize) {
+	b->wcsize = b->wcsize ? b->wcsize * 1.5 : 512;
+	if (! (b->wc = Xrealloc (b->wc, sizeof(wchar_t) * b->wcsize)) )
+	    goto error;
     }
+    rhs_string_wc = &b->wc[b->wcused];
+    b->wcused    += l + 1;
     memcpy((char *)rhs_string_wc, (char *)local_wc_buf, (l + 1) * sizeof(wchar_t) );
 
     l = _Xmbstoutf8(local_utf8_buf, rhs_string_mb, LOCAL_UTF8_BUFSIZE - 1);
     if (l == LOCAL_UTF8_BUFSIZE - 1) {
 	local_wc_buf[l] = '\0';
     }
-    if( (rhs_string_utf8 = (char *)Xmalloc(l + 1)) == NULL ) {
-	Xfree( rhs_string_wc );
-	Xfree( rhs_string_mb );
-	return( 0 );
+    while (b->utf8used + l + 1 > b->utf8size) {
+	b->utf8size = b->utf8size ? b->utf8size * 1.5 : 1024;
+	if (! (b->utf8 = Xrealloc (b->utf8, b->utf8size)) )
+	    goto error;
     }
+    rhs_string_utf8 = &b->utf8[b->utf8used];
+    b->utf8used    += l + 1;
     memcpy(rhs_string_utf8, local_utf8_buf, l + 1);
 
     for (i = 0; i < n; i++) {
-	for (p = *top; p; p = p->next) {
-	    if (buf[i].keysym        == p->keysym &&
-		buf[i].modifier      == p->modifier &&
-		buf[i].modifier_mask == p->modifier_mask) {
+	for (t = *top; t; t = b->tree[t].next) {
+	    if (buf[i].keysym        == b->tree[t].keysym &&
+		buf[i].modifier      == b->tree[t].modifier &&
+		buf[i].modifier_mask == b->tree[t].modifier_mask) {
 		break;
 	    }
 	}
-	if (p) {
+	if (t) {
+	    p = &b->tree[t];
 	    top = &p->succession;
 	} else {
-	    if( (p = (DefTree*)Xmalloc(sizeof(DefTree))) == NULL ) {
-		Xfree( rhs_string_mb );
-		goto error;
+	    while (b->treeused >= b->treesize) {
+		DefTree *old     = b->tree;
+		int      oldsize = b->treesize;
+		b->treesize = b->treesize ? b->treesize * 1.5 : 256;
+		if (! (b->tree = Xrealloc (b->tree, sizeof(DefTree) * b->treesize)) )
+		    goto error;
+		if (top >= (DTIndex *) old && top < (DTIndex *) &old[oldsize])
+		    top = (DTIndex *) (((char *) top) + (((char *)b->tree)-(char *)old));
 	    }
+	    p = &b->tree[b->treeused];
 	    p->keysym        = buf[i].keysym;
 	    p->modifier      = buf[i].modifier;
 	    p->modifier_mask = buf[i].modifier_mask;
-	    p->succession    = NULL;
+	    p->succession    = 0;
 	    p->next          = *top;
-	    p->mb            = NULL;
-	    p->wc            = NULL;
-	    p->utf8          = NULL;
+	    p->mb            = 0;
+	    p->wc            = 0;
+	    p->utf8          = 0;
 	    p->ks            = NoSymbol;
-	    *top = p;
+	    *top = b->treeused;
 	    top = &p->succession;
+	    b->treeused++;
 	}
     }
 
-    if( p->mb != NULL )
-	Xfree( p->mb );
-    p->mb = rhs_string_mb;
-    if( p->wc != NULL )
-	Xfree( p->wc );
-    p->wc = rhs_string_wc;
-    if( p->utf8 != NULL )
-	Xfree( p->utf8 );
-    p->utf8 = rhs_string_utf8;
-    p->ks = rhs_keysym;
+    /* old entries no longer freed... */
+    p->mb   = rhs_string_mb   - b->mb;
+    p->wc   = rhs_string_wc   - b->wc;
+    p->utf8 = rhs_string_utf8 - b->utf8;
+    p->ks   = rhs_keysym;
     return(n);
 error:
     while (token != ENDOFLINE && token != ENDOFFILE) {
diff --git a/modules/im/ximcp/imThaiFlt.c b/modules/im/ximcp/imThaiFlt.c
index 18df0e1f..ac851963 100644
--- a/modules/im/ximcp/imThaiFlt.c
+++ b/modules/im/ximcp/imThaiFlt.c
@@ -522,9 +522,9 @@ Private Bool ThaiComposeConvert(
  * Macros to save and recall last input character in XIC
  */
 #define IC_SavePreviousChar(ic,ch) \
-		(*((ic)->private.local.context->mb) = (char) (ch))
+                ((ic)->private.local.base.mb[(ic)->private.local.base.tree[(ic)->private.local.context].mb] = (char) (ch))
 #define IC_ClearPreviousChar(ic) \
-		(*((ic)->private.local.context->mb) = 0)
+                ((ic)->private.local.base.mb[(ic)->private.local.base.tree[(ic)->private.local.context].mb] = 0)
 #define IC_GetPreviousChar(ic) \
 		(IC_RealGetPreviousChar(ic,1))
 #define IC_GetContextChar(ic) \
@@ -536,6 +536,7 @@ Private unsigned char
 IC_RealGetPreviousChar(Xic ic, unsigned short pos)
 {
     XICCallback* cb = &ic->core.string_conversion_callback;
+    DefTreeBase *b = &ic->private.local.base;
 
     if (cb && cb->callback) {
         XIMStringConversionCallbackStruct screc;
@@ -552,7 +553,7 @@ IC_RealGetPreviousChar(Xic ic, unsigned short pos)
 
         (cb->callback)((XIC)ic, cb->client_data, (XPointer)&screc);
         if (!screc.text)
-            return (unsigned char) *((ic)->private.local.context->mb);
+            return (unsigned char) b->mb[b->tree[(ic)->private.local.context].mb];
         if ((screc.text->feedback &&
              *screc.text->feedback == XIMStringConversionLeftEdge) ||
             screc.text->length < 1)
@@ -570,7 +571,7 @@ IC_RealGetPreviousChar(Xic ic, unsigned short pos)
         XFree(screc.text);
         return c;
     } else {
-        return (unsigned char) *((ic)->private.local.context->mb);
+        return (unsigned char) b->mb[b->tree[(ic)->private.local.context].mb];
     }
 }
 
@@ -1193,13 +1194,14 @@ Private void InitIscMode(Xic ic)
 Private Bool
 ThaiFltAcceptInput(Xic ic, unsigned char new_char, KeySym symbol)
 {
-    ic->private.local.composed->wc[0] = tis2ucs(new_char);
-    ic->private.local.composed->wc[1] = '\0';
+    DefTreeBase *b = &ic->private.local.base;
+    b->wc[b->tree[ic->private.local.composed].wc+0] = tis2ucs(new_char);
+    b->wc[b->tree[ic->private.local.composed].wc+1] = '\0';
 
     if ((new_char <= 0x1f) || (new_char == 0x7f))
-        ic->private.local.composed->keysym = symbol;
+        b->tree[ic->private.local.composed].keysym = symbol;
     else
-        ic->private.local.composed->keysym = NoSymbol;
+        b->tree[ic->private.local.composed].keysym = NoSymbol;
 
     return True;
 }
@@ -1207,12 +1209,13 @@ ThaiFltAcceptInput(Xic ic, unsigned char new_char, KeySym symbol)
 Private Bool
 ThaiFltReorderInput(Xic ic, unsigned char previous_char, unsigned char new_char)
 {
+    DefTreeBase *b = &ic->private.local.base;
     if (!IC_DeletePreviousChar(ic)) return False;
-    ic->private.local.composed->wc[0] = tis2ucs(new_char);
-    ic->private.local.composed->wc[1] = tis2ucs(previous_char);
-    ic->private.local.composed->wc[2] = '\0';
+    b->wc[b->tree[ic->private.local.composed].wc+0] = tis2ucs(new_char);
+    b->wc[b->tree[ic->private.local.composed].wc+1] = tis2ucs(previous_char);
+    b->wc[b->tree[ic->private.local.composed].wc+2] = '\0';
 
-    ic->private.local.composed->keysym = NoSymbol;
+    b->tree[ic->private.local.composed].keysym = NoSymbol;
 
     return True;
 }
@@ -1220,14 +1223,15 @@ ThaiFltReorderInput(Xic ic, unsigned char previous_char, unsigned char new_char)
 Private Bool
 ThaiFltReplaceInput(Xic ic, unsigned char new_char, KeySym symbol)
 {
+    DefTreeBase *b = &ic->private.local.base;
     if (!IC_DeletePreviousChar(ic)) return False;
-    ic->private.local.composed->wc[0] = tis2ucs(new_char);
-    ic->private.local.composed->wc[1] = '\0';
+    b->wc[b->tree[ic->private.local.composed].wc+0] = tis2ucs(new_char);
+    b->wc[b->tree[ic->private.local.composed].wc+1] = '\0';
 
     if ((new_char <= 0x1f) || (new_char == 0x7f))
-        ic->private.local.composed->keysym = symbol;
+        b->tree[ic->private.local.composed].keysym = symbol;
     else
-        ic->private.local.composed->keysym = NoSymbol;
+        b->tree[ic->private.local.composed].keysym = NoSymbol;
 
     return True;
 }
@@ -1256,6 +1260,7 @@ XPointer	client_data;
 #endif
     wchar_t	    wbuf[10];
     Bool            isReject;
+    DefTreeBase    *b = &ic->private.local.base;
 
     if ((ev->type != KeyPress)
         || (ev->xkey.keycode == 0))
@@ -1358,11 +1363,11 @@ XPointer	client_data;
         return True;
     }
 
-    _Xlcwcstombs(ic->core.im->core.lcd, ic->private.local.composed->mb,
-		 ic->private.local.composed->wc, 10);
+    _Xlcwcstombs(ic->core.im->core.lcd, &b->mb[b->tree[ic->private.local.composed].mb],
+		 &b->wc[b->tree[ic->private.local.composed].wc], 10);
 
-    _Xlcmbstoutf8(ic->core.im->core.lcd, ic->private.local.composed->utf8,
-		  ic->private.local.composed->mb, 10);
+    _Xlcmbstoutf8(ic->core.im->core.lcd, &b->utf8[b->tree[ic->private.local.composed].utf8],
+		  &b->mb[b->tree[ic->private.local.composed].mb], 10);
 
     /* Remember the last character inputted
      * (as fallback in case StringConversionCallback is not provided)
diff --git a/modules/im/ximcp/imThaiIc.c b/modules/im/ximcp/imThaiIc.c
index 67d7cc26..73cf7f1e 100644
--- a/modules/im/ximcp/imThaiIc.c
+++ b/modules/im/ximcp/imThaiIc.c
@@ -62,6 +62,8 @@ _XimThaiDestroyIC(
     XIC	 xic)
 {
     Xic	 ic = (Xic)xic;
+    DefTreeBase *b = &ic->private.local.base;
+
     if(((Xim)ic->core.im)->private.local.current_ic == (XIC)ic) {
 	_XimThaiUnSetFocus(xic);
     }
@@ -70,14 +72,14 @@ _XimThaiDestroyIC(
 	ic->private.local.ic_resources = NULL;
     }
 
-    Xfree(ic->private.local.context->mb);
-    Xfree(ic->private.local.context->wc);
-    Xfree(ic->private.local.context->utf8);
-    Xfree(ic->private.local.context);
-    Xfree(ic->private.local.composed->mb);
-    Xfree(ic->private.local.composed->wc);
-    Xfree(ic->private.local.composed->utf8);
-    Xfree(ic->private.local.composed);
+    if (b->tree)  Xfree (b->tree);
+    if (b->mb)    Xfree (b->mb);
+    if (b->wc)    Xfree (b->wc);
+    if (b->utf8)  Xfree (b->utf8);
+    b->tree = NULL;
+    b->mb   = NULL;
+    b->wc   = NULL;
+    b->utf8 = NULL;
     return;
 }
 
@@ -107,11 +109,12 @@ _XimThaiReset(
     XIC	 xic)
 {
     Xic	 ic = (Xic)xic;
+    DefTreeBase *b   = &ic->private.local.base;
     ic->private.local.thai.comp_state = 0;
     ic->private.local.thai.keysym = 0;
-    ic->private.local.composed->mb[0] = '\0';
-    ic->private.local.composed->wc[0] = 0;
-    ic->private.local.composed->utf8[0] = '\0';
+    b->mb[b->tree[ic->private.local.composed].mb] = '\0';
+    b->wc[b->tree[ic->private.local.composed].wc] = '\0';
+    b->utf8[b->tree[ic->private.local.composed].utf8] = '\0';
 }
 
 Private char *
@@ -154,6 +157,7 @@ _XimThaiCreateIC(
     XIMResourceList	 res;
     unsigned int	 num;
     int			 len;
+    DefTree             *tree;
 
     if((ic = (Xic)Xmalloc(sizeof(XicRec))) == (Xic)NULL) {
 	return ((XIC)NULL);
@@ -163,30 +167,23 @@ _XimThaiCreateIC(
     ic->methods = &Thai_ic_methods;
     ic->core.im = im;
     ic->core.filter_events = KeyPressMask;
-    if ((ic->private.local.context = (DefTree *)Xmalloc(sizeof(DefTree)))
-		== (DefTree *)NULL)
-	goto Set_Error;
-    if ((ic->private.local.context->mb = (char *)Xmalloc(10))
-		== (char *)NULL)
-	goto Set_Error;
-    if ((ic->private.local.context->wc = (wchar_t *)Xmalloc(10*sizeof(wchar_t)))
-		== (wchar_t *)NULL)
-	goto Set_Error;
-    if ((ic->private.local.context->utf8 = (char *)Xmalloc(10))
-		== (char *)NULL)
-	goto Set_Error;
-    if ((ic->private.local.composed = (DefTree *)Xmalloc(sizeof(DefTree)))
-	    == (DefTree *)NULL)
+
+    if (! (ic->private.local.base.tree = tree = (DefTree *)Xmalloc(sizeof(DefTree)*3)) )
 	goto Set_Error;
-    if ((ic->private.local.composed->mb = (char *)Xmalloc(10))
-		== (char *)NULL)
+    if (! (ic->private.local.base.mb = (char *)Xmalloc(21)) )
 	goto Set_Error;
-    if ((ic->private.local.composed->wc = (wchar_t *)Xmalloc(10*sizeof(wchar_t)))
-		== (wchar_t *)NULL)
+    if (! (ic->private.local.base.wc = (wchar_t*)Xmalloc(sizeof(wchar_t)*21)) )
 	goto Set_Error;
-    if ((ic->private.local.composed->utf8 = (char *)Xmalloc(10))
-		== (char *)NULL)
+    if (! (ic->private.local.base.utf8 = (char *)Xmalloc(21)) )
 	goto Set_Error;
+    ic->private.local.context = 1;
+    tree[1].mb   = 1;
+    tree[1].wc   = 1;
+    tree[1].utf8 = 1;
+    ic->private.local.composed = 2;
+    tree[2].mb   = 11;
+    tree[2].wc   = 11;
+    tree[2].utf8 = 11;
 
     ic->private.local.thai.comp_state = 0;
     ic->private.local.thai.keysym = 0;
diff --git a/src/XlibInt.c b/src/XlibInt.c
index 1d2f5ead..1f6230cd 100644
--- a/src/XlibInt.c
+++ b/src/XlibInt.c
@@ -3371,6 +3371,26 @@ int _XOpenFile(path, flags)
     return ret;
 }
 
+int _XOpenFileMode(path, flags, mode)
+    _Xconst char* path;
+    int flags;
+    mode_t mode;
+{
+    char buf[MAX_PATH];
+    char* bufp = NULL;
+    int ret = -1;
+    UINT olderror = SetErrorMode (SEM_FAILCRITICALERRORS);
+
+    if (AccessFile (path, buf, MAX_PATH, &bufp))
+	ret = open (bufp, flags, mode);
+
+    (void) SetErrorMode (olderror);
+
+    if (bufp != buf) Xfree (bufp);
+
+    return ret;
+}
+
 void* _XFopenFile(path, mode)
     _Xconst char* path;
     _Xconst char* mode;
diff --git a/src/xlibi18n/XimintL.h b/src/xlibi18n/XimintL.h
index 1036a62b..5eeb21f2 100644
--- a/src/xlibi18n/XimintL.h
+++ b/src/xlibi18n/XimintL.h
@@ -40,21 +40,36 @@ THIS SOFTWARE.
 #define	COMPOSE_FILE	"Compose"
 
 /*
- * Data Structure for Local Processing
+ * Data Structures for Local Processing
  */
+typedef INT32  DTIndex;
+typedef INT32  DTCharIndex;
+typedef BITS32 DTModifier;
+
 typedef struct _DefTree {
-    struct _DefTree *next; 		/* another Key definition */
-    struct _DefTree *succession;	/* successive Key Sequence */
+    DTIndex          next;
+    DTIndex          succession;	/* successive Key Sequence */
 					/* Key definitions */
-    unsigned         modifier_mask;
-    unsigned         modifier;
+    DTModifier       modifier_mask;
+    DTModifier       modifier;
     KeySym           keysym;		/* leaf only */
-    char            *mb;
-    wchar_t         *wc;		/* make from mb */
-    char            *utf8;		/* make from mb */
+    DTCharIndex      mb;
+    DTCharIndex      wc;		/* make from mb */
+    DTCharIndex      utf8;		/* make from mb */
     KeySym           ks;
 } DefTree;
 
+typedef struct _DefTreeBase {
+    DefTree         *tree;
+    char            *mb;
+    wchar_t         *wc;
+    char            *utf8;
+    DTIndex          treeused, treesize;
+    DTCharIndex      mbused,   mbsize;
+    DTCharIndex      wcused,   wcsize;
+    DTCharIndex      utf8used, utf8size;
+} DefTreeBase;
+
 typedef struct _XimLocalPrivateRec {
 	/* The first fields are identical with XimCommonPrivateRec. */
 	XlcConv		 ctom_conv;
@@ -67,7 +82,8 @@ typedef struct _XimLocalPrivateRec {
 	XlcConv		 ucstoutf8_conv;
 
 	XIC		 current_ic;
-	DefTree		*top;
+	DefTreeBase	 base;
+	DTIndex          top;
 } XimLocalPrivateRec;
 
 typedef struct _XicThaiPart {
@@ -78,8 +94,9 @@ typedef struct _XicThaiPart {
 
 typedef struct _XicLocalPrivateRec {
 	long			 value_mask;
-	DefTree			*context;
-	DefTree			*composed;
+	DefTreeBase              base;
+	DTIndex			 context;
+	DTIndex			 composed;
 	XicThaiPart		 thai;
 
 	XIMResourceList		 ic_resources;