From 1400bdc09a63ff7ddbe1d66c340cc8ad50da75c1 Mon Sep 17 00:00:00 2001
From: Ilya Gorbunov <ilya.gorbunov@jetbrains.com>
Date: Thu, 29 Oct 2015 20:43:32 +0300
Subject: [PATCH] Do not allow removeSurrounding remove overlapping prefix and
 suffix.

---
 libraries/stdlib/src/kotlin/text/Strings.kt | 4 ++--
 libraries/stdlib/test/text/StringTest.kt    | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/libraries/stdlib/src/kotlin/text/Strings.kt b/libraries/stdlib/src/kotlin/text/Strings.kt
index 84f6171a0e8..2c1794d9444 100644
--- a/libraries/stdlib/src/kotlin/text/Strings.kt
+++ b/libraries/stdlib/src/kotlin/text/Strings.kt
@@ -534,7 +534,7 @@ public fun String.removeSuffix(suffix: CharSequence): String {
  * Otherwise returns a new char sequence with the same characters.
  */
 public fun CharSequence.removeSurrounding(prefix: CharSequence, suffix: CharSequence): CharSequence {
-    if (startsWith(prefix) && endsWith(suffix)) {
+    if ((length >= prefix.length + suffix.length) && startsWith(prefix) && endsWith(suffix)) {
         return subSequence(prefix.length, length - suffix.length)
     }
     return subSequence(0, length)
@@ -546,7 +546,7 @@ public fun CharSequence.removeSurrounding(prefix: CharSequence, suffix: CharSequ
  * Otherwise returns this string unchanged.
  */
 public fun String.removeSurrounding(prefix: CharSequence, suffix: CharSequence): String {
-    if (startsWith(prefix) && endsWith(suffix)) {
+    if ((length >= prefix.length + suffix.length) && startsWith(prefix) && endsWith(suffix)) {
         return substring(prefix.length, length - suffix.length)
     }
     return this
diff --git a/libraries/stdlib/test/text/StringTest.kt b/libraries/stdlib/test/text/StringTest.kt
index 2c61cf5c2dd..ea72873484e 100644
--- a/libraries/stdlib/test/text/StringTest.kt
+++ b/libraries/stdlib/test/text/StringTest.kt
@@ -436,6 +436,8 @@ class StringTest {
         assertEquals("<value", "<value".removeSurrounding(pre, post), "Only removes surrounding when both prefix and suffix present")
         assertEquals("value>", "value>".removeSurrounding(pre, post), "Only removes surrounding when both prefix and suffix present")
         assertEquals("value", "value".removeSurrounding(pre, post))
+
+        assertEquals("<->", "<->".removeSurrounding(arg1("<-"), arg1("->")), "Does not remove overlapping prefix and suffix")
     }
 
     @test fun removePrefixCharSequence() = withTwoCharSequenceArgs { arg1, arg2 ->
@@ -466,6 +468,8 @@ class StringTest {
         assertContentEquals("<value", "<value".removeSurrounding("<", ">"), "Only removes surrounding when both prefix and suffix present")
         assertContentEquals("value>", "value>".removeSurrounding("<", ">"), "Only removes surrounding when both prefix and suffix present")
         assertContentEquals("value", "value".removeSurrounding("<", ">"))
+
+        assertContentEquals("<->", "<->".removeSurrounding("<-", "->"), "Does not remove overlapping prefix and suffix")
     }
 
     /*