[PATCH 2/3] xdiff: refactor a function

["Phillip Wood via GitGitGadget" <gitgitgadget@gmail.com>]

From: Phillip Wood <phillip.wood@dunelm.org.uk>

Rather than having to remember exactly what to free after an
allocation failure use the standard "goto out" pattern. This will
simplify the next commit that starts handling currently unhandled
failures.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
---
 xdiff/xmerge.c | 36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index fff0b594f9a..48c5e9e3f35 100644
--- a/xdiff/xmerge.c
+++ b/xdiff/xmerge.c
@@ -684,35 +684,30 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1,
 int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
 		xmparam_t const *xmp, mmbuffer_t *result)
 {
-	xdchange_t *xscr1, *xscr2;
-	xdfenv_t xe1, xe2;
-	int status;
+	xdchange_t *xscr1 = NULL, *xscr2 = NULL;
+	xdfenv_t xe1 = { 0 }, xe2 = { 0 };
+	int status = -1;
 	xpparam_t const *xpp = &xmp->xpp;
 
 	result->ptr = NULL;
 	result->size = 0;
 
-	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0) {
-		return -1;
-	}
-	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
-		xdl_free_env(&xe1);
-		return -1;
-	}
+	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0)
+		goto out;
+
+	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0)
+		goto out;
+
 	if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
 	    xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
-	    xdl_build_script(&xe1, &xscr1) < 0) {
-		xdl_free_env(&xe1);
-		return -1;
-	}
+	    xdl_build_script(&xe1, &xscr1) < 0)
+		goto out;
+
 	if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
 	    xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
-	    xdl_build_script(&xe2, &xscr2) < 0) {
-		xdl_free_script(xscr1);
-		xdl_free_env(&xe1);
-		xdl_free_env(&xe2);
-		return -1;
-	}
+	    xdl_build_script(&xe2, &xscr2) < 0)
+		goto out;
+
 	status = 0;
 	if (!xscr1) {
 		result->ptr = xdl_malloc(mf2->size);
@@ -727,6 +722,7 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
 				      &xe2, xscr2,
 				      xmp, result);
 	}
+ out:
 	xdl_free_script(xscr1);
 	xdl_free_script(xscr2);
 
-- 
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