Merge branch 'ps/apply-leakfix'

"git apply" had custom buffer management code that predated before
use of strbuf got widespread, which has been updated to use strbuf,
which also plugged some memory leaks.

* ps/apply-leakfix:
  apply: refactor `struct image` to use a `struct strbuf`
  apply: rename members that track line count and allocation length
  apply: refactor code to drop `line_allocated`
  apply: introduce macro and function to init images
  apply: rename functions operating on `struct image`
  apply: reorder functions to move image-related things together

t/t3436-rebase-more-options.sh

@@ -5,6 +5,7 @@
 
 test_description='tests to ensure compatibility between am and interactive backends'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh

t/t4107-apply-ignore-whitespace.sh

@@ -3,9 +3,9 @@
 # Copyright (c) 2009 Giuseppe Bilotta
 #
 
-test_description='git-apply --ignore-whitespace.
+test_description='git-apply --ignore-whitespace.'
 
-'
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # This primes main.c file that indents without using HT at all.

t/t4124-apply-ws-rule.sh

@@ -2,6 +2,7 @@
 
 test_description='core.whitespace rules and git apply'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 prepare_test_file () {

t/t4125-apply-ws-fuzz.sh

@@ -2,6 +2,7 @@
 
 test_description='applying patch that has broken whitespaces in context'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '

t/t4138-apply-ws-expansion.sh

@@ -5,6 +5,7 @@
 
 test_description='git apply test patches with whitespace expansion.'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '