Merge #16441: build: remove qt libjpeg check from bitcoin_qt.m4

f509e3b doc: remove line numbers from qt package links (fanquake)
1bb1661 doc: fix typo in bitcoin_qt.m4 comment (fanquake)
0aeb98a build: remove jpeg lib check from bitcoin_qt.m4 (fanquake)
98a64bd build: disable libjpeg in qt (fanquake)

Pull request description:

  When gitian building on Windows I'm seeing:
  ```bash
  checking for Qt 5... yes
  checking for > Qt 5.7... yes
  checking for main in -limm32... yes
  checking for main in -lz ... yes
  checking for library containing jpeg_create_decompress ... configure: WARNING: libjpeg not found. Assuming qt has it built-in
  no
  checking for library containing png_error ... -lqtlibpng
  checking for library containing pcre2_match_16... -lqtpcre2
  checking for library containing hb_ot_tags_from_script ... -lqtharfbuzz
  ```

  We are passing `-qt-libjpeg` to Qt:
  https://github.com/bitcoin/bitcoin/blob/e6e99d4f757f2e5052f0cc68951c75e91e4753e3/depends/packages/qt.mk#L66
  but I dont think we are doing anything with `jpeg` related regardless?

ACKs for top commit:
  laanwj:
    ACK f509e3b
  promag:
    ACK f509e3b.

Tree-SHA512: 61ea20c11df11b9d426644df9a01aac12b76897003121a283fc784a8c30e9b5ad34c9805069fec20926f7aa279e59528e2e13697a944a22760c3acb6366fffbe

Author: laanwj

build-aux/m4/bitcoin_qt.m4

@@ -268,7 +268,7 @@ AC_DEFUN([_BITCOIN_QT_CHECK_QT5],[
 
 dnl Internal. Check if the included version of Qt is greater than Qt58.
 dnl Requires: INCLUDES must be populated as necessary.
-dnl Output: bitcoin_cv_qt5=yes|no
+dnl Output: bitcoin_cv_qt58=yes|no
 AC_DEFUN([_BITCOIN_QT_CHECK_QT58],[
   AC_CACHE_CHECK(for > Qt 5.7, bitcoin_cv_qt58,[
   AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
@@ -468,7 +468,6 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
   ])
 
   BITCOIN_QT_CHECK(AC_CHECK_LIB([z] ,[main],,AC_MSG_WARN([zlib not found. Assuming qt has it built-in])))
-  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([jpeg_create_decompress] ,[qtjpeg jpeg],,AC_MSG_WARN([libjpeg not found. Assuming qt has it built-in])))
   if test x$bitcoin_cv_qt58 = xno; then
     BITCOIN_QT_CHECK(AC_SEARCH_LIBS([png_error] ,[qtpng png],,AC_MSG_WARN([libpng not found. Assuming qt has it built-in])))
     BITCOIN_QT_CHECK(AC_SEARCH_LIBS([pcre16_exec], [qtpcre pcre16],,AC_MSG_WARN([libpcre16 not found. Assuming qt has it built-in])))

depends/packages/qt.mk

@@ -39,6 +39,7 @@ $(package)_config_opts += -no-ico
 $(package)_config_opts += -no-iconv
 $(package)_config_opts += -no-kms
 $(package)_config_opts += -no-linuxfb
+$(package)_config_opts += -no-libjpeg
 $(package)_config_opts += -no-libudev
 $(package)_config_opts += -no-mtdev
 $(package)_config_opts += -no-openvg
@@ -64,7 +65,6 @@ $(package)_config_opts += -pch
 $(package)_config_opts += -pkg-config
 $(package)_config_opts += -prefix $(host_prefix)
 $(package)_config_opts += -qt-libpng
-$(package)_config_opts += -qt-libjpeg
 $(package)_config_opts += -qt-pcre
 $(package)_config_opts += -qt-harfbuzz
 $(package)_config_opts += -system-zlib

doc/dependencies.md

@@ -7,25 +7,24 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | --- | --- | --- | --- | --- | --- |
 | Berkeley DB | [4.8.30](https://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html) | 4.8.x | No |  |  |
 | Boost | [1.70.0](https://www.boost.org/users/download/) | [1.47.0](https://github.com/bitcoin/bitcoin/pull/8920) | No |  |  |
-| Clang |  | [3.3+](https://llvm.org/releases/download.html) (C++11 support) |  |  |  |
+| Clang |  | [3.3+](https://releases.llvm.org/download.html) (C++11 support) |  |  |  |
 | Expat | [2.2.7](https://libexpat.github.io/) |  | No | Yes |  |
 | fontconfig | [2.12.1](https://www.freedesktop.org/software/fontconfig/release/) |  | No | Yes |  |
 | FreeType | [2.7.1](https://download.savannah.gnu.org/releases/freetype) |  | No |  |  |
 | GCC |  | [4.8+](https://gcc.gnu.org/) (C++11 support) |  |  |  |
 | HarfBuzz-NG |  |  |  |  |  |
 | libevent | [2.1.8-stable](https://github.com/libevent/libevent/releases) | 2.0.22 | No |  |  |
-| libjpeg |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L65) |
-| libpng |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L64) |
+| libpng |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | librsvg | |  |  |  |  |
 | MiniUPnPc | [2.0.20180203](http://miniupnp.free.fr/files) |  | No |  |  |
 | OpenSSL | [1.0.1k](https://www.openssl.org/source) |  | Yes |  |  |
-| PCRE |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L66) |
+| PCRE |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | protobuf | [2.6.1](https://github.com/google/protobuf/releases) |  | No |  |  |
 | Python (tests) |  | [3.5](https://www.python.org/downloads) |  |  |  |
 | qrencode | [3.4.4](https://fukuchi.org/works/qrencode) |  | No |  |  |
 | Qt | [5.9.7](https://download.qt.io/official_releases/qt/) | [5.5.1](https://github.com/bitcoin/bitcoin/issues/13478) | No |  |  |
-| XCB |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L87) (Linux only) |
-| xkbcommon |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L86) (Linux only) |
+| XCB |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) (Linux only) |
+| xkbcommon |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) (Linux only) |
 | ZeroMQ | [4.3.1](https://github.com/zeromq/libzmq/releases) | 4.0.0 | No |  |  |
 | zlib | [1.2.11](https://zlib.net/) |  |  |  | No |