Add patch support

README.md

@@ -57,6 +57,12 @@ If PHP PEAR is down you can install PHP without PEAR. Specify `PHP_WITHOUT_PEAR`
 PHP_WITHOUT_PEAR=yes asdf install php <version>
 ```
 
+#### Patch support
+
+```
+PHP_APPLY_PATCHES=$'dir/1.patch\n2.patch\nhttp://example.com/3.patch' asdf install php 7.1.1
+```
+
 ## Usage
 
 Check [asdf](https://github.com/asdf-vm/asdf) readme for instructions on how to

bin/install

@@ -6,6 +6,7 @@ install_php() {
   local install_type=$1
   local version=$2
   local install_path=$3
+  local start_dir=$(pwd)
 
   if [ "$TMPDIR" = "" ]; then
     local tmp_download_dir=$(mktemp -d)
@@ -79,6 +80,8 @@ install_php() {
 
     cd $(untar_path $install_type $version $tmp_download_dir)
 
+    apply_custom_patches "$start_dir" || exit 1
+
     # Target is OS-specific
     # target=$(get_target)
 
@@ -109,6 +112,43 @@ install_composer() {
   $bin_path/php -r "unlink('composer-setup.php');"
 }
 
+apply_custom_patches() {
+  local start_dir=$1
+  while read -r line; do
+    if [ "$line" = "" ]; then
+      continue
+    fi
+    # define earlier, so that the exit 1 shorthand below works
+    local content
+    if [[ "$line" =~ ^[Hh][Tt][Tt][Pp][Ss]?:// ]]; then
+      echo "Applying patch from URL: $line"
+      content=$(curl -Sfs "$line") || exit 1
+    else
+      local abs_path=$(get_absolute_path "$start_dir" "$line")
+      echo "Applying local patch: $abs_path"
+      content=$(<"$abs_path") || exit 1
+    fi
+
+    local striplevel=0
+    grep -q '^diff --git a/' <<< "$content" && striplevel=1
+    patch -p$striplevel --force <<< "$content" || exit 1
+  done <<< "$PHP_APPLY_PATCHES"
+}
+
+get_absolute_path() {
+  local start_dir=$1
+  local rel_path=$2
+  local rel_dir=$(dirname "$rel_path")
+  local rel_base=$(basename "$rel_path")
+
+  (
+    cd "$start_dir" \
+      && cd "$rel_dir" 2>/dev/null \
+      && echo "$(pwd)/$rel_base" \
+      || echo "$rel_path"
+  )
+}
+
 construct_configure_options() {
   local install_path=$1