use git tag based version, also generate Python project version from that

Colorama Python project uses a version string not compliant with PEP 440.
So we substitute it with a somewhat PEP 440 conformant string generated
from Git tag, corresponding unequivocally to the package's pkgver.

2 files changed, 29 insertions, 16 deletions

diff --git a/.SRCINFO b/.SRCINFO
index 8ce7accfaebe..df17f703b9b5 100644
--- a/.SRCINFO
+++ b/.SRCINFO
@@ -1,7 +1,8 @@
 pkgbase = python2-colorama-git
 	pkgdesc = Simple cross-plaform colored terminal text in Python 2
-	pkgver = 0.4.5.pre.0.4.1.r101.gaff7fb2
+	pkgver = 0.4.4.r50.gaff7fb2
 	pkgrel = 1
+	epoch = 1
 	url = https://github.com/tartley/colorama
 	arch = any
 	license = BSD
diff --git a/PKGBUILD b/PKGBUILD
index 1759dc7368f4..13ffe27c86a4 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -2,8 +2,9 @@
 # Contributor: jyantis <yantis@yantis.net>
 
 pkgname=python2-colorama-git
-pkgver=0.4.5.pre.0.4.1.r101.gaff7fb2
+pkgver=0.4.4.r50.gaff7fb2
 pkgrel=1
+epoch=1
 pkgdesc='Simple cross-plaform colored terminal text in Python 2'
 arch=('any')
 url='https://github.com/tartley/colorama'
@@ -15,20 +16,7 @@ sha256sums=('SKIP')
 provides=('python2-colorama')
 conflicts=('python2-colorama')
 
-pkgver() {
-  cd colorama
-  set -o pipefail
-  _gitversion=$( git describe --long | sed -r 's/([^-]*-g)/r\1/;s/-/./g' ||
-  printf "r%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)" )
-
-  if [ -f "colorama/__init__.py" ]; then
-      printf "%s.%s" "$(grep -R "__version__ =" colorama/__init__.py | awk -F\' '{print $2}')" $_gitversion | sed 's/-/./g'
-  else
-    printf "%s" $_gitversion
-  fi
-}
-
-build() {
+prepare() {
   cd colorama
 
   # Patch any #!/usr/bin/python to #!/usr/bin/python2
@@ -36,7 +24,31 @@ build() {
     sed -r -i 's_^#!.*/usr/bin/python(\s|$)_#!/usr/bin/python2_' $file
     sed -r -i 's_^#!.*/usr/bin/env(\s)*python(\s|$)_#!/usr/bin/env python2_' $file
   done
+}
+
+pkgver() {
+  cd colorama
+
+  # Generate git tag based version. Count only proper (v)#.#* [#=number] tags.
+  local _gitversion=$(git describe --long --tags --match '[v0-9][0-9.][0-9.]*' | sed -e 's|^v||') 
+
+  # Generate Python-compatible SCM version from git version
+  local _py_project_scm_version=$(echo $_gitversion | sed \
+    -e 's|\-\([0-9]\+\)-\(g[0-9a-f]\+\)|.dev\1+\2|'
+  )
+
+  # Replace project version with generated Python-compatible SCM version
+  sed -i -e "s|^__version__.\+\$|__version__ = '${_py_project_scm_version}'|" './colorama/__init__.py'
 
+  # Format git-based version for pkgver
+  echo $_gitversion | sed \
+    -e 's|^\([0-9][0-9.]*\)-\([a-zA-Z]\+\)|\1\2|' \
+    -e 's|\([0-9]\+-g\)|r\1|' \
+    -e 's|-|.|g'
+}
+
+build() {
+  cd colorama
   python2 setup.py build
 }