Revise build number computation

Use commits since last change to VERSION file instead of commits since
last tag. Build number is appended if VERSION ends in -dev or -pre. To
maintain consistency for 0.5.0-dev versions, the number of commits is
incremented by one for these (last tag was one commit before change to
VERSION).

base/version.jl

@@ -206,9 +206,18 @@ A `VersionNumber` object describing which version of Julia is in use. For detail
 [Version Number Literals](:ref:`man-version-number-literals`).
 """
 const VERSION = try
-    # Include build number if we've got at least some distance from a tag (e.g. a release)
-    build_number = GIT_VERSION_INFO.build_number != 0 ? "+$(GIT_VERSION_INFO.build_number)" : ""
-    convert(VersionNumber, "$(VERSION_STRING)$(build_number)")
+    ver = convert(VersionNumber, VERSION_STRING)
+    if !isempty(ver.prerelease)
+        build_number = GIT_VERSION_INFO.build_number
+        if ver == v"0.5.0-pre"
+            # due to change of reference for counting commits from last tag to last change of VERSION file
+            build_number += 5578
+        end
+        ver = VersionNumber(ver.major, ver.minor, ver.patch, ver.prerelease, (build_number,))
+    elseif GIT_VERSION_INFO.build_number != 0
+        println("WARNING: ignoring non-zero build number for VERSION")
+    end
+    ver
 catch e
     println("while creating Base.VERSION, ignoring error $e")
     VersionNumber(0)

base/version_git.sh

@@ -30,7 +30,6 @@ origin=$(git config -l 2>/dev/null | grep 'remote\.\w*\.url.*JuliaLang/julia.git
 if [ -z "$origin" ]; then
     origin="origin/"
 fi
-last_tag=$(git describe --tags --abbrev=0)
 git_time=$(git log -1 --pretty=format:%ct)
 
 #collect the contents
@@ -41,10 +40,15 @@ if [ -n "$(git status --porcelain)" ]; then
     commit_short="$commit_short"*
 fi
 branch=$(git branch | sed -n '/\* /s///p')
-# Some versions of wc (eg on OS X) add extra whitespace to their output.
-# The sed(1) call stops this from breaking the generated Julia's indentation by
-# stripping all non-digits.
-build_number=$(git rev-list HEAD ^$last_tag | wc -l | sed -e 's/[^[:digit:]]//g')
+
+topdir=$(git rev-parse --show-toplevel)
+verchanged=$(git blame -L ,1 -sl -- "$topdir/VERSION" | cut -f 1 -d " ")
+if [ $verchanged = 0000000000000000000000000000000000000000 ]; then
+    # uncommited change to VERSION
+    build_number=0
+else
+    build_number=$(git rev-list --count HEAD "^$verchanged")
+fi
 
 date_string=$git_time
 case $(uname) in

contrib/commit-name.sh

@@ -6,7 +6,34 @@
 
 gitref=${1:-HEAD}
 
-last_tag=$(git describe --tags --abbrev=0 "$gitref")
 ver=$(git show "$gitref:VERSION")
-nb=$(git rev-list --count "$gitref" "^$last_tag")
-echo "$ver+$nb"
+major=$(echo $ver | cut -f 1 -d .)
+minor=$(echo $ver | cut -f 2 -d .)
+
+if [ $major = 0 -a $minor -lt 5 ]; then
+    # use tag based build number prior to 0.5.0-
+    last_tag=$(git describe --tags --abbrev=0 "$gitref")
+    nb=$(git rev-list --count "$gitref" "^$last_tag")
+    if [ $nb = 0 ]; then
+        echo $ver
+    else
+        echo "$ver+$nb"
+    fi
+else
+    topdir=$(git rev-parse --show-toplevel)
+    verchanged=$(git blame -L ,1 -sl $gitref -- "$topdir/VERSION" | cut -f 1 -d " ")
+    nb=$(git rev-list --count "$gitref" "^$verchanged")
+    pre=$(echo $ver | cut -s -f 2 -d "-")
+    if [ $ver = "0.5.0-dev" ]; then
+        # bump to 0.5.0-dev was one commit after tag during 0.5.0-dev
+        nb=$(expr $nb + 1)
+    elif [ $ver = "0.5.0-pre" ]; then
+        # bump to 0.5.0-pre was 5578 commits after tag
+        nb=$(expr $nb + 5578)
+    fi
+    if [ -n "$pre" ]; then
+        echo "$ver+$nb"
+    else
+        echo $ver
+    fi
+fi