From cf901026037f9d9fc39ea3fdb6383c5fe1622f81 Mon Sep 17 00:00:00 2001
From: Eric Mader <emader@svn.icu-project.org>
Date: Thu, 20 Jun 2002 22:23:58 +0000
Subject: [PATCH] ICU-1068 allow for zero entry, exit anchor table offsets.
 Reset cursiveFirstPosition in resetCursiveLastExitPoint.

X-SVN-Rev: 8911
---
 .../layout/CursiveAttachmentSubtables.cpp     | 32 +++++++++++++++----
 icu4c/source/layout/GlyphIterator.cpp         |  1 +
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/icu4c/source/layout/CursiveAttachmentSubtables.cpp b/icu4c/source/layout/CursiveAttachmentSubtables.cpp
index a57e77db61e..3f4bf76673b 100644
--- a/icu4c/source/layout/CursiveAttachmentSubtables.cpp
+++ b/icu4c/source/layout/CursiveAttachmentSubtables.cpp
@@ -31,7 +31,7 @@ le_uint32 CursiveAttachmentSubtable::process(GlyphIterator *glyphIterator, const
 
     LEPoint entryAnchor, exitAnchor, pixels;
 
-    if (glyphIterator->hasCursiveLastExitPoint()) {
+    if (glyphIterator->hasCursiveLastExitPoint() && entryExitRecords[coverageIndex].entryAnchor != 0) {
         Offset entryOffset = SWAPW(entryExitRecords[coverageIndex].entryAnchor);
 
         const AnchorTable *entryAnchorTable = (const AnchorTable *) ((char *) this + entryOffset);
@@ -65,16 +65,34 @@ le_uint32 CursiveAttachmentSubtable::process(GlyphIterator *glyphIterator, const
 
     Offset exitOffset = SWAPW(entryExitRecords[coverageIndex].exitAnchor);
 
-    const AnchorTable *exitAnchorTable = (const AnchorTable *) ((char *) this + exitOffset);
+    if (exitOffset != 0) {
+        const AnchorTable *exitAnchorTable = (const AnchorTable *) ((char *) this + exitOffset);
 
-    exitAnchorTable->getAnchor(glyphID, fontInstance, exitAnchor);
+        exitAnchorTable->getAnchor(glyphID, fontInstance, exitAnchor);
 
-    if (!glyphIterator->hasCursiveFirstExitPoint()) {
-        glyphIterator->setCursiveFirstExitPoint();
+        if (!glyphIterator->hasCursiveFirstExitPoint()) {
+            glyphIterator->setCursiveFirstExitPoint();
+        }
+
+        glyphIterator->setCursiveLastExitPoint(exitAnchor);
+    } else {
+        /*
+         * We've got a glyph which is covered but doesn't have an
+         * exit point. We call setCursiveLastExitPoint just to set
+         * the position of this glyph, then resetCursiveLastExitPoint
+         * to do any baseline adjustments that are required for the
+         * sequence of attached glyphs.
+         *
+         * NOTE: we don't really care about the value of
+         * extiAnchor, because after we reset the last exit
+         * point, it won't be used. This is a bit of a hack.
+         * There should probably be a setCursiveLastExitPoint
+         * call that doesn't take an anchor...
+         */
+        glyphIterator->setCursiveLastExitPoint(exitAnchor);
+        glyphIterator->resetCursiveLastExitPoint();
     }
 
-    glyphIterator->setCursiveLastExitPoint(exitAnchor);
-
     return 1;
 }
 
diff --git a/icu4c/source/layout/GlyphIterator.cpp b/icu4c/source/layout/GlyphIterator.cpp
index 552e9b17b86..6dd4e8ca7c6 100644
--- a/icu4c/source/layout/GlyphIterator.cpp
+++ b/icu4c/source/layout/GlyphIterator.cpp
@@ -316,6 +316,7 @@ void GlyphIterator::resetCursiveLastExitPoint()
     }
 
     cursiveLastPosition       = -1;
+    cursiveFirstPosition      = -1;
     cursiveBaselineAdjustment =  0;
 }
 #endif