path: root/src/3rdparty
diff options
authorEskil Abrahamsen Blomfeldt <>2012-05-22 12:29:54 +0200
committerQt by Nokia <>2012-05-29 11:35:21 +0200
commit2e6b8b4734710377e25c199e3ff7865628e7d723 (patch)
treeb522833ac2c49f59121b29407cc39a2187ae1020 /src/3rdparty
parent291b05e4b209b79798a0f5615b50c1393fcf0961 (diff)
Disable GSUB feature when text contains surrogates
This is a work-around for a feature missing in Harfbuzz that can make a text run that contains a surrogate and a ligature crash. This will potentially cause the ligatures to break up if you combine them with a surrogate, causing visual changes to the text, but the scripts that require GSUB should not be affected by this, since they will not use surrogates. Still, it's not a permanent fix, but will serve as a bandaid for the crash until the underlying problem has been fixed. Task-number: QTBUG-22275 Change-Id: I90c37fba76bc7d1f369f3afddd1bd0dc306f5750 Reviewed-by: Jiang Jiang <>
Diffstat (limited to 'src/3rdparty')
1 files changed, 12 insertions, 1 deletions
diff --git a/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp b/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp
index 2e1b5322d2..6f663d5f9b 100644
--- a/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp
+++ b/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp
@@ -882,6 +882,17 @@ HB_Bool HB_SelectScript(HB_ShaperItem *shaper_item, const HB_OpenTypeFeature *fe
return true;
+static HB_Bool containsSurrogates(HB_ShaperItem *item)
+ for (hb_uint32 i=0; i<item->stringLength; ++i) {
+ HB_UChar16 ucs = item->string[i];
+ if ( HB_IsHighSurrogate(ucs) || HB_IsLowSurrogate(ucs) )
+ return true;
+ }
+ return false;
HB_Bool HB_OpenTypeShape(HB_ShaperItem *item, const hb_uint32 *properties)
HB_GlyphAttributes *tmpAttributes;
@@ -921,7 +932,7 @@ HB_Bool HB_OpenTypeShape(HB_ShaperItem *item, const hb_uint32 *properties)
face->glyphs_substituted = false;
- if (face->gsub) {
+ if (face->gsub && !containsSurrogates(item)) {
unsigned int error = HB_GSUB_Apply_String(face->gsub, face->buffer);
if (error && error != HB_Err_Not_Covered)
return false;