Merge branch 'js/patience-diff'

* js/patience-diff:
  bash completions: Add the --patience option
  Introduce the diff option '--patience'
  Implement the patience diff algorithm

Conflicts:
	contrib/completion/git-completion.bash

Documentation/diff-options.txt

@@ -36,6 +36,9 @@ endif::git-format-patch[]
 --patch-with-raw::
 	Synonym for "-p --raw".
 
+--patience:
+	Generate a diff using the "patience diff" algorithm.
+
 --stat[=width[,name-width]]::
 	Generate a diffstat.  You can override the default
 	output width for 80-column terminal by "--stat=width".

Makefile

@@ -1287,7 +1287,7 @@ $(LIB_FILE): $(LIB_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
 
 XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
-	xdiff/xmerge.o
+	xdiff/xmerge.o xdiff/xpatience.o
 $(XDIFF_OBJS): xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
 	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
 

contrib/completion/git-completion.bash

@@ -783,6 +783,7 @@ __git_diff_common_options="--stat --numstat --shortstat --summary
 			--no-ext-diff
 			--no-prefix --src-prefix= --dst-prefix=
 			--inter-hunk-context=
+			--patience
 			--raw
 "
 

diff.c

@@ -2474,6 +2474,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
 	else if (!strcmp(arg, "--ignore-space-at-eol"))
 		options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
+	else if (!strcmp(arg, "--patience"))
+		options->xdl_opts |= XDF_PATIENCE_DIFF;
 
 	/* flags options */
 	else if (!strcmp(arg, "--binary")) {

t/t4033-diff-patience.sh

@@ -0,0 +1,168 @@
+#!/bin/sh
+
+test_description='patience diff algorithm'
+
+. ./test-lib.sh
+
+cat >file1 <<\EOF
+#include <stdio.h>
+
+// Frobs foo heartily
+int frobnitz(int foo)
+{
+    int i;
+    for(i = 0; i < 10; i++)
+    {
+        printf("Your answer is: ");
+        printf("%d\n", foo);
+    }
+}
+
+int fact(int n)
+{
+    if(n > 1)
+    {
+        return fact(n-1) * n;
+    }
+    return 1;
+}
+
+int main(int argc, char **argv)
+{
+    frobnitz(fact(10));
+}
+EOF
+
+cat >file2 <<\EOF
+#include <stdio.h>
+
+int fib(int n)
+{
+    if(n > 2)
+    {
+        return fib(n-1) + fib(n-2);
+    }
+    return 1;
+}
+
+// Frobs foo heartily
+int frobnitz(int foo)
+{
+    int i;
+    for(i = 0; i < 10; i++)
+    {
+        printf("%d\n", foo);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    frobnitz(fib(10));
+}
+EOF
+
+cat >expect <<\EOF
+diff --git a/file1 b/file2
+index 6faa5a3..e3af329 100644
+--- a/file1
++++ b/file2
+@@ -1,26 +1,25 @@
+ #include <stdio.h>
+ 
++int fib(int n)
++{
++    if(n > 2)
++    {
++        return fib(n-1) + fib(n-2);
++    }
++    return 1;
++}
++
+ // Frobs foo heartily
+ int frobnitz(int foo)
+ {
+     int i;
+     for(i = 0; i < 10; i++)
+     {
+-        printf("Your answer is: ");
+         printf("%d\n", foo);
+     }
+ }
+ 
+-int fact(int n)
+-{
+-    if(n > 1)
+-    {
+-        return fact(n-1) * n;
+-    }
+-    return 1;
+-}
+-
+ int main(int argc, char **argv)
+ {
+-    frobnitz(fact(10));
++    frobnitz(fib(10));
+ }
+EOF
+
+test_expect_success 'patience diff' '
+
+	test_must_fail git diff --no-index --patience file1 file2 > output &&
+	test_cmp expect output
+
+'
+
+test_expect_success 'patience diff output is valid' '
+
+	mv file2 expect &&
+	git apply < output &&
+	test_cmp expect file2
+
+'
+
+cat >uniq1 <<\EOF
+1
+2
+3
+4
+5
+6
+EOF
+
+cat >uniq2 <<\EOF
+a
+b
+c
+d
+e
+f
+EOF
+
+cat >expect <<\EOF
+diff --git a/uniq1 b/uniq2
+index b414108..0fdf397 100644
+--- a/uniq1
++++ b/uniq2
+@@ -1,6 +1,6 @@
+-1
+-2
+-3
+-4
+-5
+-6
++a
++b
++c
++d
++e
++f
+EOF
+
+test_expect_success 'completely different files' '
+
+	test_must_fail git diff --no-index --patience uniq1 uniq2 > output &&
+	test_cmp expect output
+
+'
+
+test_done

xdiff/xdiff.h

@@ -32,6 +32,7 @@ extern "C" {
 #define XDF_IGNORE_WHITESPACE (1 << 2)
 #define XDF_IGNORE_WHITESPACE_CHANGE (1 << 3)
 #define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 4)
+#define XDF_PATIENCE_DIFF (1 << 5)
 #define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE | XDF_IGNORE_WHITESPACE_AT_EOL)
 
 #define XDL_PATCH_NORMAL '-'

xdiff/xdiffi.c

@@ -329,6 +329,9 @@ int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	xdalgoenv_t xenv;
 	diffdata_t dd1, dd2;
 
+	if (xpp->flags & XDF_PATIENCE_DIFF)
+		return xdl_do_patience_diff(mf1, mf2, xpp, xe);
+
 	if (xdl_prepare_env(mf1, mf2, xpp, xe) < 0) {
 
 		return -1;

xdiff/xdiffi.h

@@ -55,5 +55,7 @@ int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr);
 void xdl_free_script(xdchange_t *xscr);
 int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 		  xdemitconf_t const *xecfg);
+int xdl_do_patience_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+		xdfenv_t *env);
 
 #endif /* #if !defined(XDIFFI_H) */