Specify negative substr length (#1274)

RblSb · web-flow · commit 646aaee8e6ef · 2025-12-08T08:01:44.000+01:00
diff --git a/src/String.cpp b/src/String.cpp
@@ -1962,10 +1962,7 @@ String String::substr(int inFirst, Dynamic inLen) const
    if (inFirst<0) inFirst = 0;
    if (len<0)
    {
-      len += length;
-      // This logic matches flash ....
-      if (inFirst + len >=length)
-         len = 0;
+      len = length + len - inFirst;
    }
 
    if (len<=0 || inFirst>=length)

Original file line number	Diff line number	Diff line change
`@@ -1962,10 +1962,7 @@ String String::substr(int inFirst, Dynamic inLen) const`
`1962`	`1962`	`if (inFirst<0) inFirst = 0;`
`1963`	`1963`	`if (len<0)`
`1964`	`1964`	`{`
`1965`		`- len += length;`
`1966`		`- // This logic matches flash ....`
`1967`		`- if (inFirst + len >=length)`
`1968`		`- len = 0;`
	`1965`	`+ len = length + len - inFirst;`
`1969`	`1966`	`}`
`1970`	`1967`
`1971`	`1968`	`if (len<=0 \|\| inFirst>=length)`