add p in C tweaks

From: Phillip Wood <[email protected]>

This simplifies the code slightly, especially the third case where hunk_nr was incremented a few lines before ALLOC_GROW().

Signed-off-by Phillip Wood <[email protected]>

---
 add-patch.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

add-patch.c +4 -9

index f899389e2c..a15fa407be 100644
@@ -457,11 +457,9 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 			eol = pend;
 
 		if (starts_with(p, "diff ")) {
-			s->file_diff_nr++;
-			ALLOC_GROW(s->file_diff, s->file_diff_nr,
+			ALLOC_GROW_BY(s->file_diff, s->file_diff_nr, 1,
 				   file_diff_alloc);
 			file_diff = s->file_diff + s->file_diff_nr - 1;
-			memset(file_diff, 0, sizeof(*file_diff));
 			hunk = &file_diff->head;
 			hunk->start = p - plain->buf;
 			if (colored_p)

@@ -483,11 +481,9 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 				 */
 				hunk->splittable_into++;
 
-			file_diff->hunk_nr++;
-			ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
+			ALLOC_GROW_BY(file_diff->hunk, file_diff->hunk_nr, 1,
 				   file_diff->hunk_alloc);
 			hunk = file_diff->hunk + file_diff->hunk_nr - 1;
-			memset(hunk, 0, sizeof(*hunk));
 
 			hunk->start = p - plain->buf;
 			if (colored)

@@ -511,7 +507,7 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 			if (file_diff->mode_change)
 				BUG("double mode change?\n\n%.*s",
 				    (int)(eol - plain->buf), plain->buf);
-			if (file_diff->hunk_nr++)
+			if (file_diff->hunk_nr)
 				BUG("mode change in the middle?\n\n%.*s",
 				    (int)(eol - plain->buf), plain->buf);
 

@@ -520,9 +516,8 @@ static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 			 * is _part of_ the header "hunk".
 			 */
 			file_diff->mode_change = 1;
-			ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
+			ALLOC_GROW_BY(file_diff->hunk, file_diff->hunk_nr, 1,
 				   file_diff->hunk_alloc);
-			memset(file_diff->hunk, 0, sizeof(struct hunk));
 			file_diff->hunk->start = p - plain->buf;
 			if (colored_p)
 				file_diff->hunk->colored_start =

From: Phillip Wood <[email protected]>

When a file has been deleted the C version of add -p allows the user to edit a hunk even though 'e' is not in the list of allowed responses. (I think 'e' is disallowed because if the file is edited it is no longer a deletion and we're not set up to rewrite the diff header).

The invalid response was allowed because the test that determines whether to display 'e' was not duplicated correctly in the code that processes the user's choice. Fix this by using flags that are set when constructing the prompt and checked when processing the user's choice rather than repeating the check itself.

Signed-off-by Phillip Wood <[email protected]>

---
 add-patch.c | 54 +++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 38 insertions(+), 16 deletions(-)

add-patch.c +38 -17

index a15fa407be..907c05b3c1 100644
@@ -1352,6 +1352,15 @@ static int patch_update_file(struct add_p_state *s,
 	struct child_process cp = CHILD_PROCESS_INIT;
 	int colored = !!s->colored.len, quit = 0;
 	enum prompt_mode_type prompt_mode_type;
+	enum {
+		ALLOW_GOTO_PREVIOUS_HUNK = 1 << 0,
+		ALLOW_GOTO_PREVIOUS_UNDECIDED_HUNK = 1 << 1,
+		ALLOW_GOTO_NEXT_HUNK = 1 << 2,
+		ALLOW_GOTO_NEXT_UNDECIDED_HUNK = 1 << 3,
+		ALLOW_SEARCH_AND_GOTO = 1 << 4,
+		ALLOW_SPLIT = 1 << 5,
+		ALLOW_EDIT = 1 << 6
+	} permitted = 0;
 
 	if (!file_diff->hunk_nr)
 		return 0;

@@ -1388,22 +1397,35 @@ static int patch_update_file(struct add_p_state *s,
 		fputs(s->buf.buf, stdout);
 
 		strbuf_reset(&s->buf);
-		if (undecided_previous >= 0)
+		if (undecided_previous >= 0) {
+			permitted |= ALLOW_GOTO_PREVIOUS_UNDECIDED_HUNK;
 			strbuf_addstr(&s->buf, ",k");
-		if (hunk_index)
+		}
+		if (hunk_index) {
+			permitted |= ALLOW_GOTO_PREVIOUS_HUNK;
 			strbuf_addstr(&s->buf, ",K");
-		if (undecided_next >= 0)
+		}
+		if (undecided_next >= 0) {
+			permitted |= ALLOW_GOTO_NEXT_UNDECIDED_HUNK;
 			strbuf_addstr(&s->buf, ",j");
-		if (hunk_index + 1 < file_diff->hunk_nr)
+		}
+		if (hunk_index + 1 < file_diff->hunk_nr) {
+			permitted |= ALLOW_GOTO_NEXT_HUNK;
 			strbuf_addstr(&s->buf, ",J");
-		if (file_diff->hunk_nr > 1)
+		}
+		if (file_diff->hunk_nr > 1) {
+			permitted |= ALLOW_SEARCH_AND_GOTO;
 			strbuf_addstr(&s->buf, ",g,/");
-		if (hunk->splittable_into > 1)
+		}
+		if (hunk->splittable_into > 1) {
+			permitted |= ALLOW_SPLIT;
 			strbuf_addstr(&s->buf, ",s");
+		}
 		if (hunk_index + 1 > file_diff->mode_change &&
-		    !file_diff->deleted)
+		    !file_diff->deleted) {
+			permitted |= ALLOW_EDIT;
 			strbuf_addstr(&s->buf, ",e");
-
+		}
 		if (file_diff->deleted)
 			prompt_mode_type = PROMPT_DELETION;
 		else if (file_diff->added)

@@ -1452,22 +1474,22 @@ static int patch_update_file(struct add_p_state *s,
 				break;
 			}
 		} else if (s->answer.buf[0] == 'K') {
-			if (hunk_index)
+			if (permitted & ALLOW_GOTO_PREVIOUS_HUNK)
 				hunk_index--;
 			else
 				err(s, _("No previous hunk"));
 		} else if (s->answer.buf[0] == 'J') {
-			if (hunk_index + 1 < file_diff->hunk_nr)
+			if (permitted & ALLOW_GOTO_NEXT_HUNK)
 				hunk_index++;
 			else
 				err(s, _("No next hunk"));
 		} else if (s->answer.buf[0] == 'k') {
-			if (undecided_previous >= 0)
+			if (permitted & ALLOW_GOTO_PREVIOUS_UNDECIDED_HUNK)
 				hunk_index = undecided_previous;
 			else
 				err(s, _("No previous hunk"));
 		} else if (s->answer.buf[0] == 'j') {
-			if (undecided_next >= 0)
+			if (permitted & ALLOW_GOTO_NEXT_UNDECIDED_HUNK)
 				hunk_index = undecided_next;
 			else
 				err(s, _("No next hunk"));

@@ -1475,7 +1497,7 @@ static int patch_update_file(struct add_p_state *s,
 			char *pend;
 			unsigned long response;
 
-			if (file_diff->hunk_nr < 2) {
+			if (!(permitted & ALLOW_SEARCH_AND_GOTO)) {
 				err(s, _("No other hunks to goto"));
 				continue;
 			}

@@ -1512,7 +1534,7 @@ static int patch_update_file(struct add_p_state *s,
 			regex_t regex;
 			int ret;
 
-			if (file_diff->hunk_nr < 2) {
+			if (!(permitted & ALLOW_SEARCH_AND_GOTO)) {
 				err(s, _("No other hunks to search"));
 				continue;
 			}

@@ -1557,7 +1579,7 @@ static int patch_update_file(struct add_p_state *s,
 			hunk_index = i;
 		} else if (s->answer.buf[0] == 's') {
 			size_t splittable_into = hunk->splittable_into;
-			if (splittable_into < 2)
+			if (!(permitted & ALLOW_SPLIT))
 				err(s, _("Sorry, cannot split this hunk"));
 			else if (!split_hunk(s, file_diff,
 					     hunk - file_diff->hunk))

@@ -1565,7 +1587,7 @@ static int patch_update_file(struct add_p_state *s,
 						 _("Split into %d hunks."),
 						 (int)splittable_into);
 		} else if (s->answer.buf[0] == 'e') {
-			if (hunk_index + 1 == file_diff->mode_change)
+			if (!(permitted & ALLOW_EDIT))
 				err(s, _("Sorry, cannot edit this hunk"));
 			else if (edit_hunk_loop(s, file_diff, hunk) >= 0) {
 				hunk->use = USE_HUNK;
--

gitgitgadget

A code cleanup and small bug fix for the C version of add -p

dscho has pointed out that the bug fix in the second patch gets lost in the other changes and suggested adding the last member of the enum (which fixes the bug with handling 'e') as a separate patch. I'm unsure as it feels odd to split up the introduction of the flags - I'd be interested to hear what others think.

Phillip Wood (2):
add -p: use ALLOC_GROW_BY instead of ALLOW_GROW
add -p: fix checking of user input

 add-patch.c | 67 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 42 insertions(+), 25 deletions(-)

base-commit: 47ae905ffb98cc4d4fd90083da6bc8dab55d9ecc
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-702%2Fphillipwood%2Fwip%2Fadd-p-fixes-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-702/phillipwood/wip/add-p-fixes-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/702
--
gitgitgadget

A code cleanup and small bug fix for the C version of add -p

dscho has pointed out that the bug fix in the second patch gets lost in the other changes and suggested adding the last member of the enum (which fixes the bug with handling 'e') as a separate patch. I'm unsure as it feels odd to split up the introduction of the flags - I'd be interested to hear what others think.

Phillip Wood (2):
add -p: use ALLOC_GROW_BY instead of ALLOW_GROW
add -p: fix checking of user input

 add-patch.c | 67 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 42 insertions(+), 25 deletions(-)

base-commit: 47ae905ffb98cc4d4fd90083da6bc8dab55d9ecc
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-702%2Fphillipwood%2Fwip%2Fadd-p-fixes-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-702/phillipwood/wip/add-p-fixes-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/702

Quoted 7 lines · Phillip Wood via GitGitGadget

A code cleanup and small bug fix for the C version of add -p

dscho has pointed out that the bug fix in the second patch gets lost in the other changes and suggested adding the last member of the enum (which fixes the bug with handling 'e') as a separate patch. I'm unsure as it feels odd to split up the introduction of the flags - I'd be interested to hear what others think.

Essentially, the original was doing:

- In early part of patch_update_file(), decide what option to show in s->buf using "if (undecided_previous >= 0)" etc. boolean expression that is tailored for each command;

- In later part of patch_update_file(), after getting an answer to the end user, try to use the same boolean expression that is tailored for each command to see if the given command is acceptable.

and the bug was that each pair of boolean expressions that are supposed to be identical were duplicated in two places, and one pair was not identical by mistake.

Your [2/2] fixes it by turning the above to

- In early part of patch_update_file(), decide what option to show in s->buf using "if (undecided_previous >= 0)" etc. boolean expression that is tailored for each command, *AND* record the fact that the command is allowed in the permitted bitmask.

- In later part of patch_update_file(), after getting an answer to the end user, consult the permitted bitmask computed earlier to see if the given command is acceptable.

Since there no longer is duplicated boolean expressions that are supposed to be the same but different by a bug, once this conversion is made, it is impossible to have the bug. For that reason, I do not think the suggested split makes much sense.

A much saner split, if we have to split this step into two, would be to first fix the bug keeping the code structure of the original, i.e. the later part guards the 'e' command with

	if (hunk_index + 1 == file_diff->mode_change)

but the earlier part also required !file_diff->deleted, i.e. the condition should have been

	if (hunk_index + 1 > file_diff->mode_change && !file_diff->deleted)

So without introducing enum and permitted bitmask, you can fix the bug in place, replacing the incorrect boolean condition in the later part that guards the 'e' command with a corrected one. That would be a minimum fix that can become your new [2/2], whose theme is "to fix the bug with minumum change".

On top of that, you can convert the function again to reach the final shape that writes each boolean condition only once and records the permitted commands in the bitmask. That can be your new [3/2], whose these is "to make it impossible to introduce the bug previous step fixed".

Quoted 12 lines

Phillip Wood (2):
add -p: use ALLOC_GROW_BY instead of ALLOW_GROW
add -p: fix checking of user input

 add-patch.c | 67 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 42 insertions(+), 25 deletions(-)

base-commit: 47ae905ffb98cc4d4fd90083da6bc8dab55d9ecc
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-702%2Fphillipwood%2Fwip%2Fadd-p-fixes-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-702/phillipwood/wip/add-p-fixes-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/702