Re: git-version-gen headaches

[Jim Meyering]

Jim Meyering wrote:

> Mike Frysinger wrote:
>> the current git-version-gen script and its usage in packages such as 
>> coreutils
>> is causing me headaches wrt distros.  it currently assumes one of two states:
>>      - the current tree is a valid git repo belonging to the related project
>>      - the current tree is not a git repo (all the way back to the root)
>>
>> the reports i'm getting are that some people like to maintain some of the
>> higher directories in git (perhaps even /), and so when you unpack a 
>> coreutils
>> release and attempt to compile/install it, this script is triggered since git
>> will walk back from $PWD to / to find a .git dir.
>>
>> this results either in incorrect warnings (during install), or incorrect
>> forcing of autotools to be regenerated (during maintainer/dist targets).
>>
>> further, some of the commands used in git-version-gen require write access to
>> the .git repo (i.e. git update-index --refresh), which our package management
>> tools flag as a violation (after all, building/installing packages in $PWD
>> generally should not be updating files outside of $PWD).
>
> Thanks for the report.
>
> I've included a patch below that makes the script skip the -dirty
> check (index-updating part) when appropriate.  If that's not enough,
> please demonstrate precisely what's going wrong.

Here's a complete patch:

>From 4d90f397add9b98c536a1e75405badb923af9bcb Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sat, 19 Feb 2011 20:48:36 +0100
Subject: [PATCH] git-version-gen: skip "-dirty" check when appropriate

* build-aux/git-version-gen: Don't run any git commands
when the version comes from .tarball-version.  Prior to this,
we would run git update-index --refresh even from a just-unpacked
tarball directory, and that could affect a .git/ directory in a
parent of the build directory.  Reported by Mike Frysinger.
---
 ChangeLog                 |    9 +++++++++
 build-aux/git-version-gen |   31 +++++++++++++++++++------------
 2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index d6fd3c6..0630db0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2011-02-19  Jim Meyering  <address@hidden>
+
+       git-version-gen: skip "-dirty" check when appropriate
+       * build-aux/git-version-gen: Don't run any git commands
+       when the version comes from .tarball-version.  Prior to this,
+       we would run git update-index --refresh even from a just-unpacked
+       tarball directory, and that could affect a .git/ directory in a
+       parent of the build directory.  Reported by Mike Frysinger.
+
 2011-02-19  Bruno Haible  <address@hidden>

        unictype/property-byname: Reduce the size of the 'data' segment.
diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index 68c7d64..686f703 100755
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -1,6 +1,6 @@
 #!/bin/sh
 # Print a version string.
-scriptversion=2011-01-04.17; # UTC
+scriptversion=2011-02-19.19; # UTC

 # Copyright (C) 2007-2011 Free Software Foundation, Inc.
 #
@@ -80,6 +80,7 @@ nl='

 # Avoid meddling by environment variable of the same name.
 v=
+v_from_git=

 # First see if there is a tarball-only version file.
 # then try "git describe", then default.
@@ -134,24 +135,30 @@ then
     # Change the first '-' to a '.', so version-comparing tools work properly.
     # Remove the "g" in git describe's output string, to save a byte.
     v=`echo "$v" | sed 's/-/./;s/\(.*\)-g/\1-/'`;
+    v_from_git=1
 else
     v=UNKNOWN
 fi

 v=`echo "$v" |sed 's/^v//'`

-# Don't declare a version "dirty" merely because a time stamp has changed.
-git update-index --refresh > /dev/null 2>&1
+# Test whether to append the "-dirty" suffix only if the version
+# string we're using came from git.  I.e., skip the test if it's "UNKNOWN"
+# or if it came from .tarball-version.
+if test -n "$v_from_git"; then
+  # Don't declare a version "dirty" merely because a time stamp has changed.
+  git update-index --refresh > /dev/null 2>&1

-dirty=`exec 2>/dev/null;git diff-index --name-only HEAD` || dirty=
-case "$dirty" in
-    '') ;;
-    *) # Append the suffix only if there isn't one already.
-        case $v in
-          *-dirty) ;;
-          *) v="$v-dirty" ;;
-        esac ;;
-esac
+  dirty=`exec 2>/dev/null;git diff-index --name-only HEAD` || dirty=
+  case "$dirty" in
+      '') ;;
+      *) # Append the suffix only if there isn't one already.
+          case $v in
+            *-dirty) ;;
+            *) v="$v-dirty" ;;
+          esac ;;
+  esac
+fi

 # Omit the trailing newline, so that m4_esyscmd can use the result directly.
 echo "$v" | tr -d "$nl"
--
1.7.4.1.16.g759e8