patch 9.0.0105: illegal memory access when pattern starts with illega…

…l byte

Problem:    Illegal memory access when pattern starts with illegal byte.
Solution:   Do not match a character with an illegal byte.

src/regexp.c

@@ -1641,7 +1641,11 @@ cstrchr(char_u *s, int c)
 	{
 	    if (enc_utf8 && c > 0x80)
 	    {
-		if (utf_fold(utf_ptr2char(p)) == cc)
+		int uc = utf_ptr2char(p);
+
+		// Do not match an illegal byte.  E.g. 0xff matches 0xc3 0xbf,
+		// not 0xff.
+		if ((uc < 0x80 || uc != *p) && utf_fold(uc) == cc)
 		    return p;
 	    }
 	    else if (*p == c || *p == cc)

src/testdir/test_regexp_utf8.vim

@@ -1,5 +1,7 @@
 " Tests for regexp in utf8 encoding
 
+source shared.vim
+
 func s:equivalence_test()
   let str = "A�������������廎€廕滯廕戶漲廕兕漯廕矜漁廕唸熔廕氮熄 B��廎�廎� C������廎� D���廎�廎�廎� E������������廎�廎�廎爾廕筵獐廕擔�廙�廙� F�廎� G���罌�廎� H臚藻�廎Ｓ舅廎艮落廎芬惕 I����蘑蘆蘇蠔襤����廎矜葬廙� J譬� K譯�廎唸葡廎氯惟�€ L贏躉躅醴�廎嗤虜廎筵蜈漹� M廎擔�廜� N����廜�廜��� O��������������廜�廜�廙�廙�廙�廙�廙�廙誥 P廜�漹� Q� R������廜�廜�漹曰 S�����廜飾廜戶髡廜兩掛�� T籠聾臟�廜花僧廜桑僭 U����襯讀贗躓酈��������廜聊僑廜嗤兢廜筵誘廙艮豪廙花賑廙桑趕  V廜澄嗾 W霽廕€廕�廕� X廕� Y�韃顫�廕輔廙氮辣廙� Z饕驍鬚廕�廕惚 a�獺璽瓊瓣疇������廑�廕滿廕€漸廕扭漫廕後滬廕脊滷廕喔熊廕猾悼 b��廘矜�廎�廎� c癟�����廎��� d���廘凍�廑�廎�廎� e癡矇礙禱��������廑�廎�廎�廕嫗獄廕賦瑪廙�廙� f�廘桑�廎� g��纂耀�廑腹�� h艦藹�廎€艇廎扭萱廎後�漹刷� i穫穩簾簿藺蘋蘊蠕���禸廑葉廎脊�廙� j警� k譟�廑萵廎喔葭漹虎� l贍躁躂���廎猿號廎頗蜇漹� m廘脊蛾廜� n簽����廘唸�廜�廜��� o簷籀繫繭繹繪������伂廜�廜�廙�廙�廙�廙�廙�廙﹥誨 p廘晨善廑�廜� q�� r������刓廘聊絨廑�廜��� s���禳�廘氮�廜﹥馳廜丟鳩廜抱 t籟聽襲��廘菲鼠廜凍僖廜晨�漹� u羅繳羶羹觼贖躑轡鑄鑒��������廘擔�廜喔僱廜猿凳廜頗誑廙扭貍廙後賒廙脊跼 v�廑厭廜� w霾廕�廕�廕� x廕� y羸藩韁�廕�廙喔輓廙猿遜 z驕髒鱉廘嗤�廕�廕惇"
   let groups = split(str)
@@ -560,6 +562,19 @@ func Test_match_invalid_byte()
   call delete('Xinvalid')
 endfunc
 
+func Test_match_illegal_byte()
+  let lines =<< trim END
+      silent! buffer 藩\c
+      next 藩
+      0scriptnames
+      source
+  END
+  call writefile(lines, 'Xregexp')
+  call system(GetVimCommand() .. ' -X -Z -e -s -S Xregexp -c qa!')
+
+  call delete('Xregexp')
+endfunc
+
 func Test_match_too_complicated()
   set regexpengine=1
   exe "noswapfile vsplit \xeb\xdb\x99"

src/version.c

@@ -735,6 +735,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    105,
 /**/
     104,
 /**/