Avoid negative character

k-takata · nobu · commit 54b963956b65 · 2025-10-31T20:49:59.000+09:00
Better fix for k-takata/Onigmo#107. k-takata/Onigmo@85393e4
diff --git a/enc/unicode.c b/enc/unicode.c
@@ -687,10 +687,8 @@ onigenc_unicode_case_map(OnigCaseFoldType* flagP,
 	  MODIFIED;
 	  if (flags & ONIGENC_CASE_FOLD_TURKISH_AZERI && code == 'i')
 	    code = I_WITH_DOT_ABOVE;
-          else {
-            code -= 'a';
-            code += 'A';
-          }
+          else
+            code -= 'a' - 'A';
 	}
       }
       else if (code >= 'A' && code <= 'Z') {
diff --git a/regenc.c b/regenc.c
@@ -984,7 +984,7 @@ onigenc_ascii_only_case_map(OnigCaseFoldType* flagP, const OnigUChar** pp, const
 
     if (code >= 'a' && code <= 'z' && (flags & ONIGENC_CASE_UPCASE)) {
       flags |= ONIGENC_CASE_MODIFIED;
-      code += 'A' - 'a';
+      code -= 'a' - 'A';
     }
     else if (code >= 'A' && code <= 'Z' &&
         (flags & (ONIGENC_CASE_DOWNCASE | ONIGENC_CASE_FOLD))) {
@@ -1013,7 +1013,7 @@ onigenc_single_byte_ascii_only_case_map(OnigCaseFoldType* flagP, const OnigUChar
 
     if (code >= 'a' && code <= 'z' && (flags & ONIGENC_CASE_UPCASE)) {
       flags |= ONIGENC_CASE_MODIFIED;
-      code += 'A' - 'a';
+      code -= 'a' - 'A';
     }
     else if (code >= 'A' && code <= 'Z' &&
         (flags & (ONIGENC_CASE_DOWNCASE | ONIGENC_CASE_FOLD))) {

Original file line number	Diff line number	Diff line change
`@@ -687,10 +687,8 @@ onigenc_unicode_case_map(OnigCaseFoldType* flagP,`
`687`	`687`	`MODIFIED;`
`688`	`688`	`if (flags & ONIGENC_CASE_FOLD_TURKISH_AZERI && code == 'i')`
`689`	`689`	`code = I_WITH_DOT_ABOVE;`
`690`		`- else {`
`691`		`- code -= 'a';`
`692`		`- code += 'A';`
`693`		`- }`
	`690`	`+ else`
	`691`	`+ code -= 'a' - 'A';`
`694`	`692`	`}`
`695`	`693`	`}`
`696`	`694`	`else if (code >= 'A' && code <= 'Z') {`