From 2cf04119102753e92b5dc09cd3820f5f15d4022f Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Tue, 11 May 2021 16:27:15 -0700
Subject: [PATCH] Remove String16::remove.

This function, ironically, is being removed.

Even more amusing, it was never "remove" anyway --- it literally did
the opposite, and removed everything *except* the range you passed to
it, and should probably have been called "keep"!

I'm looking at reimplementing much of libutils, but first I'm improving
test coverage, and literally every test I wrote for this failed. And
then when I fixed the "obvious bugs" in the implementation, I found
there actually were a couple of existing unit tests --- that mostly
served to demonstrate just how counter-intuitive this function was.

Bug: http://b/156999009
Test: treehugger
Change-Id: I41fd85f7c0988070f4039f607d2e57523d862ed9
---
 libutils/String16.cpp             | 32 -------------------------------
 libutils/String16_fuzz.cpp        |  8 --------
 libutils/String16_test.cpp        | 15 ---------------
 libutils/include/utils/String16.h |  2 --
 4 files changed, 57 deletions(-)

diff --git a/libutils/String16.cpp b/libutils/String16.cpp
index e3e5f1106..faf90c233 100644
--- a/libutils/String16.cpp
+++ b/libutils/String16.cpp
@@ -411,36 +411,4 @@ status_t String16::replaceAll(char16_t replaceThis, char16_t withThis)
     return OK;
 }
 
-status_t String16::remove(size_t len, size_t begin)
-{
-    const size_t N = size();
-    if (begin >= N) {
-        release();
-        mString = getEmptyString();
-        return OK;
-    }
-    if (len > N || len > N - begin) len = N - begin;
-    if (begin == 0 && len == N) {
-        return OK;
-    }
-
-    if (begin > 0) {
-        SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((N + 1) * sizeof(char16_t)));
-        if (!buf) {
-            return NO_MEMORY;
-        }
-        char16_t* str = (char16_t*)buf->data();
-        memmove(str, str+begin, (N-begin+1)*sizeof(char16_t));
-        mString = str;
-    }
-    SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((len + 1) * sizeof(char16_t)));
-    if (buf) {
-        char16_t* str = (char16_t*)buf->data();
-        str[len] = 0;
-        mString = str;
-        return OK;
-    }
-    return NO_MEMORY;
-}
-
 }; // namespace android
diff --git a/libutils/String16_fuzz.cpp b/libutils/String16_fuzz.cpp
index defa0f5a6..d7e5ec783 100644
--- a/libutils/String16_fuzz.cpp
+++ b/libutils/String16_fuzz.cpp
@@ -72,12 +72,6 @@ std::vector<std::function<void(FuzzedDataProvider&, android::String16, android::
                     char16_t replaceChar = dataProvider.ConsumeIntegral<char16_t>();
                     str1.replaceAll(findChar, replaceChar);
                 }),
-                ([](FuzzedDataProvider& dataProvider, android::String16 str1,
-                    android::String16) -> void {
-                    size_t len = dataProvider.ConsumeIntegral<size_t>();
-                    size_t begin = dataProvider.ConsumeIntegral<size_t>();
-                    str1.remove(len, begin);
-                }),
 };
 
 void callFunc(uint8_t index, FuzzedDataProvider& dataProvider, android::String16 str1,
@@ -111,7 +105,5 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
         callFunc(op, dataProvider, str_one_utf16, str_two_utf16);
     }
 
-    str_one_utf16.remove(0, str_one_utf16.size());
-    str_two_utf16.remove(0, str_two_utf16.size());
     return 0;
 }
diff --git a/libutils/String16_test.cpp b/libutils/String16_test.cpp
index c2e9b02cd..54662ac41 100644
--- a/libutils/String16_test.cpp
+++ b/libutils/String16_test.cpp
@@ -90,13 +90,6 @@ TEST(String16Test, Insert) {
     EXPECT_STR16EQ(u"VerifyInsert me", tmp);
 }
 
-TEST(String16Test, Remove) {
-    String16 tmp("Verify me");
-    tmp.remove(2, 6);
-    EXPECT_EQ(2U, tmp.size());
-    EXPECT_STR16EQ(u" m", tmp);
-}
-
 TEST(String16Test, ReplaceAll) {
     String16 tmp("Verify verify Verify");
     tmp.replaceAll(u'r', u'!');
@@ -161,14 +154,6 @@ TEST(String16Test, StaticStringInsert) {
     EXPECT_FALSE(tmp.isStaticString());
 }
 
-TEST(String16Test, StaticStringRemove) {
-    StaticString16 tmp(u"Verify me");
-    tmp.remove(2, 6);
-    EXPECT_EQ(2U, tmp.size());
-    EXPECT_STR16EQ(u" m", tmp);
-    EXPECT_FALSE(tmp.isStaticString());
-}
-
 TEST(String16Test, StaticStringReplaceAll) {
     StaticString16 tmp(u"Verify verify Verify");
     tmp.replaceAll(u'r', u'!');
diff --git a/libutils/include/utils/String16.h b/libutils/include/utils/String16.h
index 5ce48c684..60d523a4c 100644
--- a/libutils/include/utils/String16.h
+++ b/libutils/include/utils/String16.h
@@ -88,8 +88,6 @@ public:
             status_t            replaceAll(char16_t replaceThis,
                                            char16_t withThis);
 
-            status_t            remove(size_t len, size_t begin=0);
-
     inline  int                 compare(const String16& other) const;
 
     inline  bool                operator<(const String16& other) const;