Resolves: icu#7601, icu#8198

Change-Id: I1d0d9a322a42fe7a020d46f21bb3c52a5070c866

1 files changed, 127 insertions, 0 deletions

diff --git a/icu/icu4c.8198.revert.icu5431.patch b/icu/icu4c.8198.revert.icu5431.patch
new file mode 100644
index 000000000000..629bec099583
--- /dev/null
+++ b/icu/icu4c.8198.revert.icu5431.patch
@@ -0,0 +1,127 @@
+--- misc/icu/source/layout/IndicReordering.cpp	(revision 26090)
++++ misc/build/icu/source/layout/IndicReordering.cpp	(revision 25772)
+@@ -126,8 +126,4 @@
+     FeatureMask fSMFeatures;
+ 
+-    LEUnicode   fPreBaseConsonant;
+-    LEUnicode   fPreBaseVirama;
+-    le_int32    fPBCIndex;
+-    FeatureMask fPBCFeatures;
+ 
+     void saveMatra(LEUnicode matra, le_int32 matraIndex, IndicClassTable::CharClass matraClass)
+@@ -176,6 +172,5 @@
+           fMatraFeatures(0), fMPreOutIndex(-1), fMPreFixups(mpreFixups),
+           fVMabove(0), fVMpost(0), fVMIndex(0), fVMFeatures(0),
++          fSMabove(0), fSMbelow(0), fSMIndex(0), fSMFeatures(0)
+-          fSMabove(0), fSMbelow(0), fSMIndex(0), fSMFeatures(0),
+-          fPreBaseConsonant(0), fPreBaseVirama(0), fPBCIndex(0), fPBCFeatures(0)
+     {
+         // nothing else to do...
+@@ -196,6 +191,4 @@
+         fVMabove = fVMpost  = 0;
+         fSMabove = fSMbelow = 0;
+-
+-        fPreBaseConsonant = fPreBaseVirama = 0;
+     }
+ 
+@@ -393,12 +386,4 @@
+     }
+ 
+-    void notePreBaseConsonant(le_uint32 index,LEUnicode PBConsonant, LEUnicode PBVirama, FeatureMask features)
+-    {
+-        fPBCIndex = index;
+-        fPreBaseConsonant = PBConsonant;
+-        fPreBaseVirama = PBVirama;
+-        fPBCFeatures = features;
+-    }
+-
+     void noteBaseConsonant()
+     {
+@@ -480,20 +465,4 @@
+     }
+     
+-    void writePreBaseConsonant()
+-    {
+-        // The TDIL spec says that consonant + virama + RRA should produce a rakar in Malayalam.  However,
+-        // it seems that almost none of the fonts for Malayalam are set up to handle this.
+-        // So, we're going to force the issue here by using the rakar as defined with RA in most fonts.
+-
+-        if (fPreBaseConsonant == 0x0d31) { // RRA
+-            fPreBaseConsonant = 0x0d30; // RA
+-        }
+-        
+-        if (fPreBaseConsonant != 0) {
+-            writeChar(fPreBaseConsonant, fPBCIndex, fPBCFeatures);
+-            writeChar(fPreBaseVirama,fPBCIndex-1,fPBCFeatures);
+-        }
+-    }
+-
+     le_int32 getOutputIndex()
+     {
+@@ -754,5 +723,4 @@
+             }
+ 
+-            
+             IndicClassTable::CharClass charClass = CC_RESERVED;
+             IndicClassTable::CharClass nextClass = CC_RESERVED;
+@@ -762,9 +730,7 @@
+             le_bool  seenVattu = FALSE;
+             le_bool  seenBelowBaseForm = FALSE;
+-            le_bool  seenPreBaseForm = FALSE;
+             le_bool  hasNukta = FALSE;
+             le_bool  hasBelowBaseForm = FALSE;
+             le_bool  hasPostBaseForm = FALSE;
+-            le_bool  hasPreBaseForm = FALSE;
+ 
+             if (postBase < markStart && classTable->isNukta(chars[postBase])) {
+@@ -780,20 +746,12 @@
+                 hasBelowBaseForm = IndicClassTable::hasBelowBaseForm(charClass) && !hasNukta;
+                 hasPostBaseForm  = IndicClassTable::hasPostBaseForm(charClass)  && !hasNukta;
+-                hasPreBaseForm = IndicClassTable::hasPreBaseForm(charClass) && !hasNukta;
+ 
+                 if (IndicClassTable::isConsonant(charClass)) {
+                     if (postBaseLimit == 0 || seenVattu ||
+                         (baseConsonant > baseLimit && !classTable->isVirama(chars[baseConsonant - 1])) ||
++                        !(hasBelowBaseForm || hasPostBaseForm)) {
+-                        !(hasBelowBaseForm || hasPostBaseForm || hasPreBaseForm)) {
+                         break;
+                     }
+ 
+-                    // Note any pre-base consonants
+-                    if ( baseConsonant == lastConsonant && lastConsonant > 0 && 
+-                         hasPreBaseForm && classTable->isVirama(chars[baseConsonant - 1])) {
+-                        output.notePreBaseConsonant(lastConsonant,chars[lastConsonant],chars[lastConsonant-1],tagArray2);
+-                        seenPreBaseForm = TRUE;
+-   
+-                    }
+                     // consonants with nuktas are never vattus
+                     seenVattu = IndicClassTable::isVattu(charClass) && !hasNukta;
+@@ -828,12 +786,10 @@
+ 
+             // write any pre-base consonants
+-            output.writePreBaseConsonant();
+-
+             le_bool supressVattu = TRUE;
+ 
+             for (i = baseLimit; i < baseConsonant; i += 1) {
+                 LEUnicode ch = chars[i];
++                // Don't put 'blwf' on first consonant.
++                FeatureMask features = (i == baseLimit? tagArray2 : tagArray1);
+-                // Don't put 'pstf' or 'blwf' on anything before the base consonant.
+-                FeatureMask features = tagArray1 & ~( pstfFeatureMask | blwfFeatureMask );
+ 
+                 charClass = classTable->getCharClass(ch);
+@@ -886,5 +842,5 @@
+ 
+             // write below-base consonants
++            if (baseConsonant != lastConsonant) {
+-            if (baseConsonant != lastConsonant && !seenPreBaseForm) {
+                 for (i = bcSpan + 1; i < postBase; i += 1) {
+                     output.writeChar(chars[i], i, tagArray1);
+@@ -916,5 +872,5 @@
+             // write post-base consonants
+             // FIXME: does this put the right tags on post-base consonants?
++            if (baseConsonant != lastConsonant) {
+-            if (baseConsonant != lastConsonant && !seenPreBaseForm) {
+                 if (postBase <= lastConsonant) {
+                     for (i = postBase; i <= lastConsonant; i += 1) {