msys2-runtime: path patch fixes

Fixes for 0003-Add-msys2_path_conv.patch:
Early out case fixed, n3, n4, n5 access beyond string fixed

Added back 0004-Fix-cygwin-path_conv-of-root.patch:
It was dropped by mistake in an earlier commit

msys2-runtime/0003-Add-msys2_path_conv.patch

@@ -15,7 +15,7 @@ diff -Naur a/winsup/cygwin/Makefile.in b/winsup/cygwin/Makefile.in
 diff -Naur a/winsup/cygwin/msys2_path_conv.cc b/winsup/cygwin/msys2_path_conv.cc
 --- a/winsup/cygwin/msys2_path_conv.cc	1970-01-01 03:00:00.000000000 +0300
 +++ b/winsup/cygwin/msys2_path_conv.cc	2014-03-21 20:53:18.963200000 +0400
-@@ -0,0 +1,606 @@
+@@ -0,0 +1,608 @@
 +/*
 +  The MSYS2 Path conversion source code is licensed under:
 +  
@@ -251,7 +251,7 @@ diff -Naur a/winsup/cygwin/msys2_path_conv.cc b/winsup/cygwin/msys2_path_conv.cc
 +    }
 +
 +    copy_to_dst(copy_from, *from, dst, dstend);
-+    
++
 +    if (type != NONE) {
 +        convert_path(from, *to, type, dst, dstend);
 +    }
@@ -268,21 +268,23 @@ diff -Naur a/winsup/cygwin/msys2_path_conv.cc b/winsup/cygwin/msys2_path_conv.cc
 +    }
 +
 +    int need_convert = false;
-+    for (const char* it = src; it != '\0'; ++it) {
++    for (const char* it = src; *it != '\0'; ++it) {
 +        if (*it == '\\' || *it == '/') {
 +            need_convert = true;
 +            break;
 +        }
 +    }
 +
++    char* dstit = dst;
++    char* dstend = dst + dstlen;
 +    if (!need_convert) {
-+        return src;
++        copy_to_dst(src, NULL, &dstit, dstend);
++        *dstit = '\0';
++        return dst;
 +    }
 +
 +    const char* srcit = src;
 +    const char* srcbeg = src;
-+    char* dstit = dst;
-+    char* dstend = dst + dstlen;
 +
 +    int prev_was_space = 0;
 +    int in_string = false;
@@ -406,10 +408,10 @@ diff -Naur a/winsup/cygwin/msys2_path_conv.cc b/winsup/cygwin/msys2_path_conv.cc
 +    int starts_with_minus = (*it == '-');
 +
 +    if (starts_with_minus) {
-+        char n2 = *(it + 2);
-+        char n3 = *(it + 3);
-+        char n4 = *(it + 4);
-+        char n5 = *(it + 5);
++        char n2 =      *(it + 2);
++        char n3 = n2 ? *(it + 3) : '\0';
++        char n4 = n3 ? *(it + 4) : '\0';
++        char n5 = n4 ? *(it + 5) : '\0';
 +
 +        if (n2 == '/') {
 +            it += 2;

msys2-runtime/PKGBUILD

@@ -12,16 +12,17 @@ license=('GPL')
 groups=('base')
 depends=()
 makedepends=('cocom' 'git' 'perl' 'gcc' 'mingw-w64-cross-gcc' 'mingw-w64-cross-zlib')
-#options=('debug' '!strip')
+options=('debug' '!strip')
 source=('msys2-runtime'::'git+https://github.com/Alexpux/Cygwin.git#branch=develop'
         '0001-Expand-CYGWIN-error_start-processing.patch'
         '0002-revert-mounting.patch'
-        '0003-Add-msys2_path_conv.patch')
+        '0003-Add-msys2_path_conv.patch'
+        '0004-Fix-cygwin-path_conv-of-root.patch')
 md5sums=('SKIP'
          '85fabbc5d9cdb46cf73da9654f2c83bc'
          'ace414fde822ae633183fe94cbb0e1d9'
-         '20d6f4ba12086ade744e9360417b5b80')
-
+         'fd8d1ad7bbffbb655cc311bb70d75e49'
+         '4e39847e44316ae7376323e0b7538504')
 pkgver() {
 	cd "$srcdir/msys2-runtime"
 	#printf "%s.%s" "$(git rev-list --count HEAD)" "$(git rev-parse --short HEAD)"
@@ -35,6 +36,7 @@ prepare() {
 #	patch -p1 -i ${srcdir}/0002-revert-mounting.patch
 # This is the new code, but it doesn't handle Unix PATH lists very well.
 	patch -p1 -i ${srcdir}/0003-Add-msys2_path_conv.patch
+	patch -p1 -i ${srcdir}/0004-Fix-cygwin-path_conv-of-root.patch
 }
 
 build() {