build: Install zsh completion

Fixes #534
Closes #537

.gitignore

@@ -49,3 +49,4 @@ missing
 mkinstalldirs
 tags
 test-driver
+scripts/_curl

Makefile.am

@@ -140,7 +140,7 @@ CLEANFILES = $(VC6_LIBDSP) $(VC6_SRCDSP) $(VC7_LIBVCPROJ) $(VC7_SRCVCPROJ)	\
 
 bin_SCRIPTS = curl-config
 
-SUBDIRS = lib src include
+SUBDIRS = lib src include scripts
 DIST_SUBDIRS = $(SUBDIRS) tests packages docs
 
 pkgconfigdir = $(libdir)/pkgconfig

configure.ac

@@ -3030,6 +3030,31 @@ if test X"$want_h2" != Xno; then
 
 fi
 
+dnl **********************************************************************
+dnl Check for zsh completion path
+dnl **********************************************************************
+
+OPT_ZSH_FPATH=default
+AC_ARG_WITH(zsh-functions-dir,
+AC_HELP_STRING([--with-zsh-functions-dir=PATH],[Install zsh completions to PATH])
+AC_HELP_STRING([--without-zsh-functions-dir],[Do not install zsh completions]),
+  [OPT_ZSH_FPATH=$withval])
+case "$OPT_ZSH_FPATH" in
+  no)
+    dnl --without-zsh-functions-dir option used
+    ;;
+  default|yes)
+    dnl --with-zsh-functions-dir option used without path
+    ZSH_FUNCTIONS_DIR="$datarootdir/zsh/site-functions"
+    AC_SUBST(ZSH_FUNCTIONS_DIR)
+    ;;
+  *)
+    dnl --with-zsh-functions-dir option used with path
+    ZSH_FUNCTIONS_DIR="$withval"
+    AC_SUBST(ZSH_FUNCTIONS_DIR)
+    ;;
+esac
+
 dnl **********************************************************************
 dnl Back to "normal" configuring
 dnl **********************************************************************
@@ -3797,6 +3822,7 @@ AC_CONFIG_FILES([Makefile \
            include/curl/Makefile \
            src/Makefile \
            lib/Makefile \
+           scripts/Makefile \
            lib/libcurl.vers \
            tests/Makefile \
            tests/certs/Makefile \

scripts/Makefile.am

@@ -0,0 +1,13 @@
+ZSH_FUNCTIONS_DIR = @ZSH_FUNCTIONS_DIR@
+PERL = @PERL@
+
+ZSH_COMPLETION_FUNCTION_FILENAME = _curl
+
+all-local: $(ZSH_COMPLETION_FUNCTION_FILENAME)
+
+$(ZSH_COMPLETION_FUNCTION_FILENAME): zsh.pl
+	$(PERL) $< > $@
+
+install-data-local:
+	$(MKDIR_P) $(ZSH_FUNCTIONS_DIR)
+	$(INSTALL_DATA) $(ZSH_COMPLETION_FUNCTION_FILENAME) $(ZSH_FUNCTIONS_DIR)/$(ZSH_COMPLETION_FUNCTION_FILENAME)