Merge #17324: Update univalue subtree

fa0b3da36c Squashed 'src/univalue/' changes from 7890db99d6..5a58a46671 (MarcoFalke)

Pull request description:

  Only change is a performance improvement. See https://github.com/bitcoin-core/univalue/pull/21#issue-333858474 and https://github.com/bitcoin-core/univalue/pull/15#issue-186748173

ACKs for top commit:
  jnewbery:
    ACK fa439e88af
  laanwj:
    ACK fa439e88af

Tree-SHA512: 35ea8f76ea4806182949c8eb5a8b652d1aaeec03ee023838e7cb29abcb81c61d59b38f15708564a78574722df57d13f61ef17d0f670a4056819705ef892321e0

src/univalue/README.md

@@ -12,21 +12,10 @@ an arbitrary depth.
 This class is aligned with the JSON standard, [RFC
 7159](https://tools.ietf.org/html/rfc7159.html).
 
-## Installation
+## Library usage
 
-This project is a standard GNU
-[autotools](https://www.gnu.org/software/automake/manual/html_node/Autotools-Introduction.html)
-project.  Build and install instructions are available in the `INSTALL`
-file provided with GNU autotools.
-
-```
-$ ./autogen.sh
-$ ./configure
-$ make
-```
-
-## Design
-
-UniValue provides a single dynamic RAII C++ object class,
-and minimizes template use (contra json_spirit).
+This is a fork of univalue used by Bitcoin Core. It is not maintained for usage
+by other projects. Notably, the API may break in non-backward-compatible ways.
 
+Other projects looking for a maintained library should use the upstream
+univalue at https://github.com/jgarzik/univalue.

src/univalue/include/univalue.h

@@ -47,7 +47,6 @@ public:
         std::string s(val_);
         setStr(s);
     }
-    ~UniValue() {}
 
     void clear();
 

src/univalue/lib/univalue_get.cpp

@@ -35,7 +35,7 @@ bool ParseInt32(const std::string& str, int32_t *out)
     errno = 0; // strtol will not set errno if valid
     long int n = strtol(str.c_str(), &endp, 10);
     if(out) *out = (int32_t)n;
-    // Note that strtol returns a *long int*, so even if strtol doesn't report a over/underflow
+    // Note that strtol returns a *long int*, so even if strtol doesn't report an over/underflow
     // we still have to check that the returned value is within the range of an *int32_t*. On 64-bit
     // platforms the size of these types may be different.
     return endp && *endp == 0 && !errno &&