[mm-common] meson.build: Don't require curl or wget when use-network=false

[Kjell Ahlstedt <kjellahl src gnome org>]

commit cca2cf9588e276284fd03711ab5d7eaf4ee9e6cc
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Fri May 31 11:05:06 2019 +0200

    meson.build: Don't require curl or wget when use-network=false
    
    None of those commands is used when network access is disabled.

 meson.build                     | 14 +++++----
 util/meson_aux/libstdcxx-tag.sh | 64 ++++++++++++++++++++++-------------------
 2 files changed, 43 insertions(+), 35 deletions(-)
---
diff --git a/meson.build b/meson.build
index 17fbf43..085405f 100644
--- a/meson.build
+++ b/meson.build
@@ -226,9 +226,14 @@ install_data('README', install_dir: mm_common_docdir)
 
 # Either curl or wget is required for downloading libstdc++.tag,
 # used by Doxygen.
-curl = find_program('curl', required: false)
-if not curl.found()
-  wget = find_program('wget', required: true)
+download_cmd = 'none'
+if get_option('use-network')
+  curl = find_program('curl', required: false)
+  download_cmd = 'curl'
+  if not curl.found()
+    wget = find_program('wget', required: true)
+    download_cmd = 'wget'
+  endif
 endif
 
 # Download libstdc++.tag if it does not exist or if it's out of date.
@@ -236,8 +241,7 @@ custom_target('libstdc++.tag',
   output: 'libstdc++.tag',
   command: [
     files(join_paths('util', 'meson_aux', 'libstdcxx-tag.sh')),
-    '@0@'.format(get_option('use-network')), # true or false
-    curl.found() ? 'curl' : 'wget',
+    download_cmd,
     join_paths(meson.current_source_dir(), 'doctags'),
     '@OUTPUT@',
   ],
diff --git a/util/meson_aux/libstdcxx-tag.sh b/util/meson_aux/libstdcxx-tag.sh
index 73354a8..9ac83f2 100755
--- a/util/meson_aux/libstdcxx-tag.sh
+++ b/util/meson_aux/libstdcxx-tag.sh
@@ -2,38 +2,42 @@
 
 # External command, intended to be called with custom_target() in meson.build
 
-# libstdcxx-tag.sh <use_network> <curl-or-wget> <srcdir> <output_path>
+# libstdcxx-tag.sh <curl-or-wget-or-none> <srcdir> <output_path>
 
-output_dirname="$(dirname "$4")"
-output_filename="$(basename "$4")"
+output_dirname="$(dirname "$3")"
+output_filename="$(basename "$3")"
 
 # Remote location of the GNU libstdc++ Doxygen tag file.
 libstdcxx_tag_url="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/$output_filename";
 
-if [ "$1" != "true" ]; then
-  if [ -f "$4" ]; then
-    echo "Did not check status of $4 because network is disabled."
-  elif [ -f "$3/$output_filename" ]; then
-    echo "Warning: $4 does not exist."
-    echo "Copying from the source directory because network is disabled."
-    echo "If you want an up-to-date copy, reconfigure with the -Duse-network=true option."
-    cp --preserve=timestamps "$3/$output_filename" "$4"
-  else
-    echo "Error: $4 does not exist." >&2
-    echo "Downloading it is not possible because network is disabled." >&2
-    echo "Please reconfigure with the -Duse-network=true option." >&2
-    exit 1
-  fi
-elif [ "$2" = "curl" ]; then
-  # These options don't contain filenames, and thus no spaces that
-  # must be preserved in the call to curl.
-  simple_curl_options="--compressed --connect-timeout 300 --globoff --location --max-time 3600 --remote-time 
--retry 5"
-  if [ -f "$4" ]; then
-    curl $simple_curl_options --time-cond "$4" --output "$4" "$libstdcxx_tag_url"
-  else
-    curl $simple_curl_options --output "$4" "$libstdcxx_tag_url"
-  fi
-else
-  wget --timestamping --no-directories --timeout=300 --tries=5 \
-       --directory-prefix="$output_dirname" "$libstdcxx_tag_url"
-fi
+case "$1" in
+  curl)
+    # These options don't contain filenames, and thus no spaces that
+    # must be preserved in the call to curl.
+    simple_curl_options="--compressed --connect-timeout 300 --globoff --location --max-time 3600 
--remote-time --retry 5"
+    if [ -f "$3" ]; then
+      curl $simple_curl_options --time-cond "$3" --output "$3" "$libstdcxx_tag_url"
+    else
+      curl $simple_curl_options --output "$3" "$libstdcxx_tag_url"
+    fi
+    ;;
+  wget)
+    wget --timestamping --no-directories --timeout=300 --tries=5 \
+         --directory-prefix="$output_dirname" "$libstdcxx_tag_url"
+    ;;
+  *)
+    if [ -f "$3" ]; then
+      echo "Did not check status of $3 because network is disabled."
+    elif [ -f "$2/$output_filename" ]; then
+      echo "Warning: $3 does not exist."
+      echo "Copying from the source directory because network is disabled."
+      echo "If you want an up-to-date copy, reconfigure with the -Duse-network=true option."
+      cp --preserve=timestamps "$2/$output_filename" "$3"
+    else
+      echo "Error: $3 does not exist." >&2
+      echo "Downloading it is not possible because network is disabled." >&2
+      echo "Please reconfigure with the -Duse-network=true option." >&2
+      exit 1
+    fi
+    ;;
+esac