fix a bug in the greek shaper that could lead to an endless loop.

availableGlyphs has to be initialized before we call
stringToCMap.

Added a test case that triggered the problem.

2 files changed, 54 insertions, 13 deletions

diff --git a/src/harfbuzz-greek.c b/src/harfbuzz-greek.c
index 59f3077..2e9b858 100644
--- a/src/harfbuzz-greek.c
+++ b/src/harfbuzz-greek.c
@@ -77,10 +77,12 @@ static HB_UChar16 compose_0x300(HB_UChar16 base)
             return 0x1fdd;
         return 0;
     }
-    const hb_greek_decomposition *d = decompose_0x300;
-    while (d->base && d->base != base)
-        ++d;
-    return d->composed;
+    {
+        const hb_greek_decomposition *d = decompose_0x300;
+        while (d->base && d->base != base)
+            ++d;
+        return d->composed;
+    }
 }
 
 static const hb_greek_decomposition decompose_0x301[] = {
@@ -115,10 +117,12 @@ static HB_UChar16 compose_0x301(HB_UChar16 base)
         if (base == 0x1ffe)
             return 0x1fde;
     }
-    const hb_greek_decomposition *d = decompose_0x301;
-    while (d->base && d->base != base)
-        ++d;
-    return d->composed;
+    {
+        const hb_greek_decomposition *d = decompose_0x301;
+        while (d->base && d->base != base)
+            ++d;
+        return d->composed;
+    }
 }
 
 static const hb_greek_decomposition decompose_0x304[] = {
@@ -351,8 +355,7 @@ static HB_UChar16 compose_0x345(HB_UChar16 base)
 */
 HB_Bool HB_GreekShape(HB_ShaperItem *shaper_item)
 {
-    assert(shaper_item->item.script == HB_Script_Greek);
-
+    const int availableGlyphs = shaper_item->num_glyphs;
     const HB_UChar16 *uc = shaper_item->string + shaper_item->item.pos;
     unsigned short *logClusters = shaper_item->log_clusters;
     HB_GlyphAttributes *attributes = shaper_item->attributes;
@@ -363,6 +366,9 @@ HB_Bool HB_GreekShape(HB_ShaperItem *shaper_item)
     hb_uint32 i;
 
     HB_STACKARRAY(HB_UChar16, shapedChars, 2 * shaper_item->item.length);
+
+    assert(shaper_item->item.script == HB_Script_Greek);
+
     *shapedChars = *uc;
     logClusters[0] = 0;
 
@@ -430,7 +436,6 @@ HB_Bool HB_GreekShape(HB_ShaperItem *shaper_item)
 
 #ifndef NO_OPENTYPE
     if (HB_SelectScript(shaper_item, greek_features)) {
-        const int availableGlyphs = shaper_item->num_glyphs;
         HB_OpenTypeShape(shaper_item, /*properties*/0);
         return HB_OpenTypePosition(shaper_item, availableGlyphs, /*doLogClusters*/TRUE);
     }
diff --git a/tests/shaping/main.cpp b/tests/shaping/main.cpp
index b48b0a9..320e8ee 100644
--- a/tests/shaping/main.cpp
+++ b/tests/shaping/main.cpp
@@ -272,7 +272,6 @@ Shaper::Shaper(FT_Face face, HB_Script script, const QString &str)
 }
 
 
-#if defined(Q_WS_X11)
 static bool decomposedShaping(FT_Face face, HB_Script script, const QChar &ch)
 {
     QString uc = QString().append(ch);
@@ -318,7 +317,6 @@ static bool decomposedShaping(FT_Face face, HB_Script script, const QChar &ch)
     qDebug("    decomposed glyph result = %s", str.toLatin1().constData());
     return false;
 }
-#endif
 
 struct ShapeTable {
     unsigned short unicode[16];
@@ -382,6 +380,44 @@ void tst_QScriptEngine::greek()
                 continue;
             QVERIFY( decomposedShaping(face, HB_Script_Greek, QChar(uc)) );
         }
+        FT_Done_Face(face);
+    } else {
+        QSKIP("couln't find DejaVu Sans", SkipAll);
+    }
+
+
+    face = loadFace("SBL_grk.ttf");
+    if (face) {
+        for (int uc = 0x1f00; uc <= 0x1fff; ++uc) {
+            QString str;
+            str.append(uc);
+            if (str.normalized(QString::NormalizationForm_D).normalized(QString::NormalizationForm_C) != str) {
+                //qDebug() << "skipping" << hex << uc;
+                continue;
+            }
+            if (uc == 0x1fc1 || uc == 0x1fed)
+                continue;
+            QVERIFY( decomposedShaping(face, HB_Script_Greek, QChar(uc)) );
+
+        }
+
+        const ShapeTable shape_table [] = {
+            { { 0x3b1, 0x300, 0x313, 0x0 },
+              { 0xb8, 0x3d3, 0x3c7, 0x0 } },
+            { { 0x3b1, 0x313, 0x300, 0x0 },
+              { 0xd4, 0x0 } },
+
+            { {0}, {0} }
+        };
+
+
+        const ShapeTable *s = shape_table;
+        while (s->unicode[0]) {
+            QVERIFY( shaping(face, s, HB_Script_Greek) );
+            ++s;
+        }
+
+        FT_Done_Face(face);
     } else {
         QSKIP("couln't find DejaVu Sans", SkipAll);
     }