Merge branch 'jc/apply-ws-fix-expands' into maint

"git apply --whitespace=fix" used to under-allocate the memory
when the fix resulted in a longer text than the original patch.

* jc/apply-ws-fix-expands:
  apply: count the size of postimage correctly
  apply: make update_pre_post_images() sanity check the given postlen
  apply.c: typofix

builtin/apply.c

@@ -2230,6 +2230,12 @@ static void update_pre_post_images(struct image *preimage,
 		ctx++;
 	}
 
+	if (postlen
+	    ? postlen < new - postimage->buf
+	    : postimage->len < new - postimage->buf)
+		die("BUG: caller miscounted postlen: asked %d, orig = %d, used = %d",
+		    (int)postlen, (int) postimage->len, (int)(new - postimage->buf));
+
 	/* Fix the length of the whole thing */
 	postimage->len = new - postimage->buf;
 	postimage->nr -= reduced;
@@ -2385,18 +2391,34 @@ static int match_fragment(struct image *img,
 
 	/*
 	 * The hunk does not apply byte-by-byte, but the hash says
-	 * it might with whitespace fuzz. We haven't been asked to
+	 * it might with whitespace fuzz. We weren't asked to
 	 * ignore whitespace, we were asked to correct whitespace
 	 * errors, so let's try matching after whitespace correction.
 	 *
+	 * While checking the preimage against the target, whitespace
+	 * errors in both fixed, we count how large the corresponding
+	 * postimage needs to be.  The postimage prepared by
+	 * apply_one_fragment() has whitespace errors fixed on added
+	 * lines already, but the common lines were propagated as-is,
+	 * which may become longer when their whitespace errors are
+	 * fixed.
+	 */
+
+	/* First count added lines in postimage */
+	postlen = 0;
+	for (i = 0; i < postimage->nr; i++) {
+		if (!(postimage->line[i].flag & LINE_COMMON))
+			postlen += postimage->line[i].len;
+	}
+
+	/*
 	 * The preimage may extend beyond the end of the file,
 	 * but in this loop we will only handle the part of the
 	 * preimage that falls within the file.
 	 */
 	strbuf_init(&fixed, preimage->len + 1);
 	orig = preimage->buf;
 	target = img->buf + try;
-	postlen = 0;
 	for (i = 0; i < preimage_limit; i++) {
 		size_t oldlen = preimage->line[i].len;
 		size_t tgtlen = img->line[try_lno + i].len;
@@ -2424,7 +2446,10 @@ static int match_fragment(struct image *img,
 		match = (tgtfix.len == fixed.len - fixstart &&
 			 !memcmp(tgtfix.buf, fixed.buf + fixstart,
 					     fixed.len - fixstart));
-		postlen += tgtfix.len;
+
+		/* Add the length if this is common with the postimage */
+		if (preimage->line[i].flag & LINE_COMMON)
+			postlen += tgtfix.len;
 
 		strbuf_release(&tgtfix);
 		if (!match)

t/t4138-apply-ws-expansion.sh

@@ -0,0 +1,121 @@
+#!/bin/sh
+#
+# Copyright (C) 2015 Kyle J. McKay
+#
+
+test_description='git apply test patches with whitespace expansion.'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	#
+	## create test-N, patchN.patch, expect-N files
+	#
+
+	# test 1
+	printf "\t%s\n" 1 2 3 4 5 6 >before &&
+	printf "\t%s\n" 1 2 3 >after &&
+	printf "%64s\n" a b c >>after &&
+	printf "\t%s\n" 4 5 6 >>after &&
+	git diff --no-index before after |
+		sed -e "s/before/test-1/" -e "s/after/test-1/" >patch1.patch &&
+	printf "%64s\n" 1 2 3 4 5 6 >test-1 &&
+	printf "%64s\n" 1 2 3 a b c 4 5 6 >expect-1 &&
+
+	# test 2
+	printf "\t%s\n" a b c d e f >before &&
+	printf "\t%s\n" a b c >after &&
+	n=10 &&
+	x=1 &&
+	while test $x -lt $n
+	do
+		printf "%63s%d\n" "" $x >>after
+		x=$(( $x + 1 ))
+	done &&
+	printf "\t%s\n" d e f >>after &&
+	git diff --no-index before after |
+		sed -e "s/before/test-2/" -e "s/after/test-2/" >patch2.patch &&
+	printf "%64s\n" a b c d e f >test-2 &&
+	printf "%64s\n" a b c >expect-2 &&
+	x=1 &&
+	while test $x -lt $n
+	do
+		printf "%63s%d\n" "" $x >>expect-2
+		x=$(( $x + 1 ))
+	done &&
+	printf "%64s\n" d e f >>expect-2 &&
+
+	# test 3
+	printf "\t%s\n" a b c d e f >before &&
+	printf "\t%s\n" a b c >after &&
+	n=100 &&
+	x=0 &&
+	while test $x -lt $n
+	do
+		printf "%63s%02d\n" "" $x >>after
+		x=$(( $x + 1 ))
+	done &&
+	printf "\t%s\n" d e f >>after &&
+	git diff --no-index before after |
+	sed -e "s/before/test-3/" -e "s/after/test-3/" >patch3.patch &&
+	printf "%64s\n" a b c d e f >test-3 &&
+	printf "%64s\n" a b c >expect-3 &&
+	x=0 &&
+	while test $x -lt $n
+	do
+		printf "%63s%02d\n" "" $x >>expect-3
+		x=$(( $x + 1 ))
+	done &&
+	printf "%64s\n" d e f >>expect-3 &&
+
+	# test 4
+	>before &&
+	x=0 &&
+	while test $x -lt 50
+	do
+		printf "\t%02d\n" $x >>before
+		x=$(( $x + 1 ))
+	done &&
+	cat before >after &&
+	printf "%64s\n" a b c >>after &&
+	while test $x -lt 100
+	do
+		printf "\t%02d\n" $x >>before
+		printf "\t%02d\n" $x >>after
+		x=$(( $x + 1 ))
+	done &&
+	git diff --no-index before after |
+	sed -e "s/before/test-4/" -e "s/after/test-4/" >patch4.patch &&
+	>test-4 &&
+	x=0 &&
+	while test $x -lt 50
+	do
+		printf "%63s%02d\n" "" $x >>test-4
+		x=$(( $x + 1 ))
+	done &&
+	cat test-4 >expect-4 &&
+	printf "%64s\n" a b c >>expect-4 &&
+	while test $x -lt 100
+	do
+		printf "%63s%02d\n" "" $x >>test-4
+		printf "%63s%02d\n" "" $x >>expect-4
+		x=$(( $x + 1 ))
+	done &&
+
+	git config core.whitespace tab-in-indent,tabwidth=63 &&
+	git config apply.whitespace fix
+
+'
+
+# Note that `patch` can successfully apply all patches when run
+# with the --ignore-whitespace option.
+
+for t in 1 2 3 4
+do
+	test_expect_success 'apply with ws expansion (t=$t)' '
+		git apply patch$t.patch &&
+		test_cmp test-$t expect-$t
+	'
+done
+
+test_done