1 files changed, 27 insertions, 0 deletions
diff --git a/tests/utf.test b/tests/utf.test
index 9dd8017..e820359 100644
--- a/tests/utf.test
+++ b/tests/utf.test
@@ -44,6 +44,18 @@ test utf-1.6 {Tcl_UniCharToUtf: negative Tcl_UniChar} testbytestring {
 test utf-1.7 {Tcl_UniCharToUtf: 4 byte sequences} -constraints testbytestring -body {
     expr {"\U014e4e" eq [testbytestring "\xf0\x94\xb9\x8e"]}
 } -result 1
+test utf-1.8 {Tcl_UniCharToUtf: 3 byte sequence, upper surrogate} testbytestring {
+    expr {"\ud842" eq [testbytestring "\xed\xa1\x82"]}
+} 1
+test utf-1.9 {Tcl_UniCharToUtf: 3 byte sequence, lower surrogate} testbytestring {
+    expr {"\udc42" eq [testbytestring "\xed\xb1\x82"]}
+} 1
+test utf-1.10 {Tcl_UniCharToUtf: 3 byte sequence, upper surrogate} testbytestring {
+    expr {[format %c 0xd842] eq [testbytestring "\xed\xa1\x82"]}
+} 1
+test utf-1.11 {Tcl_UniCharToUtf: 3 byte sequence, lower surrogate} testbytestring {
+    expr {[format %c 0xdc42] eq [testbytestring "\xed\xb1\x82"]}
+} 1
 
 test utf-2.1 {Tcl_UtfToUniChar: low ascii} {
     string length "abc"
@@ -146,6 +158,12 @@ test utf-8.3 {Tcl_UniCharAtIndex: index > 0} {
 test utf-8.4 {Tcl_UniCharAtIndex: index > 0} {
     string index \u4e4e\u25a\xff\u543 2
 } "\uff"
+test utf-8.5 {Tcl_UniCharAtIndex: upper surrogate} {
+    string index \ud842 0
+} "\ud842"
+test utf-8.5 {Tcl_UniCharAtIndex: lower surrogate} {
+    string index \udc42 0
+} "\udc42"
 
 test utf-9.1 {Tcl_UtfAtIndex: index = 0} {
     string range abcd 0 2
@@ -251,6 +269,9 @@ test utf-11.4 {Tcl_UtfToUpper} {
 test utf-11.5 {Tcl_UtfToUpper Georgian (new in Unicode 11)} {
     string toupper \u10d0\u1c90
 } \u1c90\u1c90
+test utf-11.6 {Tcl_UtfToUpper low/high surrogate)} {
+    string toupper \udc24\ud824
+} \udc24\ud824
 
 test utf-12.1 {Tcl_UtfToLower} {
     string tolower {}
@@ -267,6 +288,9 @@ test utf-12.4 {Tcl_UtfToLower} {
 test utf-12.5 {Tcl_UtfToLower Georgian (new in Unicode 11)} {
     string tolower \u10d0\u1c90
 } \u10d0\u10d0
+test utf-12.6 {Tcl_UtfToUpper low/high surrogate)} {
+    string tolower \udc24\ud824
+} \udc24\ud824
 
 test utf-13.1 {Tcl_UtfToTitle} {
     string totitle {}
@@ -286,6 +310,9 @@ test utf-13.5 {Tcl_UtfToTitle Georgian (new in Unicode 11)} {
 test utf-13.6 {Tcl_UtfToTitle Georgian (new in Unicode 11)} {
     string totitle \u1c90\u10d0
 } \u1c90\u10d0
+test utf-13.7 {Tcl_UtfToTitle low/high surrogate)} {
+    string totitle \udc24\ud824
+} \udc24\ud824
 
 test utf-14.1 {Tcl_UtfNcasecmp} {
     string compare -nocase a b