build system: include git commit number since last release in version for dev builds

.gitignore

@@ -64,6 +64,7 @@
 /src/common/common_pch.h.[gp]ch
 /src/common/common_pch.h.pch-????????
 /src/common/libmtxcommon.dll
+/src/common/mkvtoolnix_version.h
 /src/info/forms/*.h
 /src/info/static_plugins.cpp
 /src/mkvextract

Rakefile

@@ -100,6 +100,8 @@ def setup_globals
   $dependency_dir          = "#{$source_dir}/rake.d/dependency.d"
   $dependency_tmp_dir      = "#{$dependency_dir}/tmp"
 
+  $version_header_name     = "#{$build_dir}/src/common/mkvtoolnix_version.h"
+
   $languages               =  {
     :programs              => c(:TRANSLATIONS).split(/\s+/),
     :manpages              => c(:MANPAGES_TRANSLATIONS).split(/\s+/),
@@ -279,6 +281,7 @@ setup_globals
 setup_overrides
 import_dependencies
 generate_helper_files
+update_version_number_include
 
 # Default task
 define_default_task
@@ -977,6 +980,7 @@ task :clean do
   }
   patterns += $applications + $tools.collect { |name| "src/tools/#{name}" }
   patterns += PCH.clean_patterns
+  patterns << $version_header_name
 
   remove_files_by_patterns patterns
 

rake.d/helpers.rb

@@ -1,4 +1,7 @@
 # coding: utf-8
+
+require "shellwords"
+
 $use_tempfile_for_run = defined?(RUBY_PLATFORM) && /mingw/i.match(RUBY_PLATFORM)
 
 $git_mutex     = Mutex.new
@@ -252,6 +255,38 @@ def ensure_file file_name, content = ""
   File.open(file_name, 'w') { |file| file.write(content) }
 end
 
+def update_version_number_include
+  git_dir         = $source_dir + '/.git'
+  current_version = nil
+  wanted_version  = c(:PACKAGE_VERSION)
+
+  if FileTest.exists?($version_header_name)
+    lines = IO.readlines($version_header_name)
+
+    if !lines.empty? && %r{#define.*?"([0-9.]+)"}.match(lines[0])
+      current_version = $1
+    end
+  end
+
+  if FileTest.directory?(git_dir)
+    command = ["git", "--git-dir=#{$source_dir}/.git", "describe", "HEAD"].
+      map { |e| Shellwords.escape(e) }.
+      join(' ')
+
+    description = `#{command} 2> /dev/null`.chomp
+
+    if %r{^release-#{Regexp.escape(c(:PACKAGE_VERSION))}-(\d+)}.match(description) && ($1.to_i != 0)
+      wanted_version += ".#{$1}"
+    end
+  end
+
+  return if current_version == wanted_version
+
+  File.open($version_header_name, "w") do |file|
+    file.puts("#define MKVTOOLNIX_VERSION \"#{wanted_version}\"")
+  end
+end
+
 class Rake::Task
   def mo_all_prerequisites
     todo   = [name]

src/common/version.cpp

@@ -18,6 +18,7 @@
 
 #include "common/debugging.h"
 #include "common/hacks.h"
+#include "common/mkvtoolnix_version.h"
 #include "common/strings/formatting.h"
 #include "common/strings/parsing.h"
 #include "common/version.h"
@@ -135,7 +136,7 @@ get_version_info(const std::string &program,
 
   if (!program.empty())
     info.push_back(program);
-  info.push_back(fmt::format("v{0} ('{1}')", PACKAGE_VERSION, VERSIONNAME));
+  info.push_back(fmt::format("v{0} ('{1}')", MKVTOOLNIX_VERSION, VERSIONNAME));
 
   if (flags & vif_architecture)
     info.push_back(fmt::format("{0}-bit", __SIZEOF_POINTER__ * 8));
@@ -145,12 +146,12 @@ get_version_info(const std::string &program,
 
 int
 compare_current_version_to(const std::string &other_version_str) {
-  return version_number_t(PACKAGE_VERSION).compare(version_number_t(other_version_str));
+  return version_number_t(MKVTOOLNIX_VERSION).compare(version_number_t(other_version_str));
 }
 
 version_number_t
 get_current_version() {
-  return version_number_t(PACKAGE_VERSION);
+  return version_number_t(MKVTOOLNIX_VERSION);
 }
 
 mtx_release_version_t