Fixed patch.eol bug that truncated all patched lines to one character

Also updated the import-eol test to test with lines longer than one character,
and also empty lines.

mercurial/patch.py

@@ -299,7 +299,7 b' class patchfile(object):'
             if self.eol and self.eol != '\n':
                 for l in lines:
                     if l and l[-1] == '\n':
-                        l = l[:1] + self.eol
+                        l = l[:-1] + self.eol
                     fp.write(l)
             else:
                 fp.writelines(lines)

tests/test-import-eol

@@ -9,9 +9,10 b" w('--- a/a\\n')"
 w('+++ b/a\n')
 w('@@ -1,5 +1,5 @@\n')
 w(' a\n')
-w('-b\r\n')
-w('+y\r\n')
-w(' c\r\n')
+w('-bbb\r\n')
+w('+yyyy\r\n')
+w(' cc\r\n')
+w(' \n')
 w(' d\n')
 w('-e\n')
 w('\ No newline at end of file\n')
@@ -24,7 +25,7 b' cd repo'
 echo '\.diff' > .hgignore
 
 # Test different --eol values
-python -c 'file("a", "wb").write("a\nb\nc\nd\ne")'
+python -c 'file("a", "wb").write("a\nbbb\ncc\n\nd\ne")'
 hg ci -Am adda
 python ../makepatch.py
 echo % invalid eol

tests/test-import-eol.out

@@ -5,11 +5,11 b' applying eol.diff'
 abort: Unsupported line endings type: LFCR
 % force LF
 applying eol.diff
-'a\ny\nc\nd\nz'
+'a\nyyyy\ncc\n\nd\ne'
 % force CRLF
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 applying eol.diff
-'a\r\ny\r\nc\r\nd\r\nz'
+'a\r\nyyyy\r\ncc\r\n\r\nd\r\ne'
 adding b
 % binary patch with --eol
 applying bin.diff