Check for the existence of git before running commands

gclient

Index: gclient
diff --git a/gclient b/gclient
index c377660002139b035e80eabda508db00a2b874d4..aeb648ecec16acac993c15d9a9cef51f7f6b4ccf 100755
--- a/gclient
+++ b/gclient
@@ -7,14 +7,50 @@
 
 base_dir=$(dirname "$0")
 
+# Test git and git --version.
+function test_git {
+  echo -n "Trying git... "
+  local GITV="$(git --version)" || {
+    echo "git isn't installed, please install it"
+    exit 1
+  }
+
+  GITV="${GITV##* }"          # Only examine last word (i.e. version number)
+  local GITD=( ${GITV//./ } ) # Split version number into decimals
+  if ((GITD[0] < 1 || (GITD[0] == 1 && GITD[1] < 6) )); then
+    echo "git version is ${GITV}, please update to a version later than 1.6"
+    exit 1
+  fi
+}
+
+# Test git svn and git svn --version.
+function test_git_svn {
+  echo -n "Trying git-svn... "

[M-A Ruel, 2010/01/08 01:12:43]

Actually, after trying the patch, I don't want this output nor line 12.

This is because it is always output otherwise. I'll commit without those lines.

+  local GITV="$(git svn --version)" || {
+    echo "git-svn isn't installed, please install it"
+    exit 1
+  }
+
+  GITV="${GITV#* version }"   # git svn --version has extra output to remove.
+  GITV="${GITV% (svn*}"
+  local GITD=( ${GITV//./ } ) # Split version number into decimals
+  if ((GITD[0] < 1 || (GITD[0] == 1 && GITD[1] < 6) )); then
+    echo "git version is ${GITV}, please update to a version later than 1.6"
+    exit 1
+  fi
+}
+
+
 # Update git checkouts prior the cygwin check, we don't want to use msysgit.
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/.git" ]
 then
+  test_git_svn
   (cd "$base_dir"; git svn rebase -q -q)
 fi
 
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" -a -e "$base_dir/git-cl-repo/.git" ]
 then
+  test_git
   (cd "$base_dir/git-cl-repo"; git pull -q)
 fi