1 3b0f3d61 2020-01-22 neels /* Produce a unidiff output from a diff_result. */
  2 3b0f3d61 2020-01-22 neels /*
  3 3b0f3d61 2020-01-22 neels  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
  4 3b0f3d61 2020-01-22 neels  *
  5 3b0f3d61 2020-01-22 neels  * Permission to use, copy, modify, and distribute this software for any
  6 3b0f3d61 2020-01-22 neels  * purpose with or without fee is hereby granted, provided that the above
  7 3b0f3d61 2020-01-22 neels  * copyright notice and this permission notice appear in all copies.
  8 3b0f3d61 2020-01-22 neels  *
  9 3b0f3d61 2020-01-22 neels  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 10 3b0f3d61 2020-01-22 neels  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 11 3b0f3d61 2020-01-22 neels  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 12 3b0f3d61 2020-01-22 neels  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 13 3b0f3d61 2020-01-22 neels  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 14 3b0f3d61 2020-01-22 neels  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 15 3b0f3d61 2020-01-22 neels  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 16 3b0f3d61 2020-01-22 neels  */
 17 3b0f3d61 2020-01-22 neels 
 18 e10a628a 2020-09-16 stsp #include <errno.h>
 19 e10a628a 2020-09-16 stsp #include <inttypes.h>
 20 e10a628a 2020-09-16 stsp #include <stdbool.h>
 21 e10a628a 2020-09-16 stsp #include <stdio.h>
 22 e10a628a 2020-09-16 stsp #include <stdlib.h>
 23 e10a628a 2020-09-16 stsp 
 24 1dfba055 2020-10-07 stsp #include <arraylist.h>
 25 1dfba055 2020-10-07 stsp #include <diff_main.h>
 26 1dfba055 2020-10-07 stsp #include <diff_output.h>
 27 3b0f3d61 2020-01-22 neels 
 28 85ab4559 2020-09-22 stsp #include "diff_internal.h"
 29 2a1b94d0 2020-09-26 stsp #include "diff_debug.h"
 30 3b0f3d61 2020-01-22 neels 
 31 61a7b578 2020-05-06 neels static bool
 32 f374e913 2020-09-22 stsp chunk_context_empty(const struct diff_chunk_context *cc)
 33 3b0f3d61 2020-01-22 neels {
 34 d362ea2e 2020-07-25 stsp 	return diff_range_empty(&cc->chunk);
 35 3b0f3d61 2020-01-22 neels }
 36 3b0f3d61 2020-01-22 neels 
 37 fe8af0d6 2020-10-06 stsp int
 38 fe8af0d6 2020-10-06 stsp diff_chunk_get_left_start(const struct diff_chunk *c,
 39 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 40 fe8af0d6 2020-10-06 stsp {
 41 fe8af0d6 2020-10-06 stsp 	int left_start = diff_atom_root_idx(&r->left, c->left_start);
 42 fe8af0d6 2020-10-06 stsp 	return MAX(0, left_start - context_lines);
 43 fe8af0d6 2020-10-06 stsp }
 44 fe8af0d6 2020-10-06 stsp 
 45 fe8af0d6 2020-10-06 stsp int
 46 fe8af0d6 2020-10-06 stsp diff_chunk_get_left_end(const struct diff_chunk *c,
 47 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 48 fe8af0d6 2020-10-06 stsp {
 49 fe8af0d6 2020-10-06 stsp 	int left_start = diff_chunk_get_left_start(c, r, 0);
 50 fe8af0d6 2020-10-06 stsp 	return MIN(r->left.atoms.len,
 51 fe8af0d6 2020-10-06 stsp 	    left_start + c->left_count + context_lines);
 52 fe8af0d6 2020-10-06 stsp }
 53 fe8af0d6 2020-10-06 stsp 
 54 fe8af0d6 2020-10-06 stsp int
 55 fe8af0d6 2020-10-06 stsp diff_chunk_get_right_start(const struct diff_chunk *c,
 56 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 57 fe8af0d6 2020-10-06 stsp {
 58 fe8af0d6 2020-10-06 stsp 	int right_start = diff_atom_root_idx(&r->right, c->right_start);
 59 fe8af0d6 2020-10-06 stsp 	return MAX(0, right_start - context_lines);
 60 fe8af0d6 2020-10-06 stsp }
 61 fe8af0d6 2020-10-06 stsp 
 62 fe8af0d6 2020-10-06 stsp int
 63 fe8af0d6 2020-10-06 stsp diff_chunk_get_right_end(const struct diff_chunk *c,
 64 fe8af0d6 2020-10-06 stsp     const struct diff_result *r, int context_lines)
 65 fe8af0d6 2020-10-06 stsp {
 66 fe8af0d6 2020-10-06 stsp 	int right_start = diff_chunk_get_right_start(c, r, 0);
 67 fe8af0d6 2020-10-06 stsp 	return MIN(r->right.atoms.len,
 68 fe8af0d6 2020-10-06 stsp 	    right_start + c->right_count + context_lines);
 69 fe8af0d6 2020-10-06 stsp }
 70 fe8af0d6 2020-10-06 stsp 
 71 f374e913 2020-09-22 stsp void
 72 f374e913 2020-09-22 stsp diff_chunk_context_get(struct diff_chunk_context *cc, const struct diff_result *r,
 73 0d27172a 2020-05-06 neels 		  int chunk_idx, int context_lines)
 74 3b0f3d61 2020-01-22 neels {
 75 3b0f3d61 2020-01-22 neels 	const struct diff_chunk *c = &r->chunks.head[chunk_idx];
 76 fe8af0d6 2020-10-06 stsp 	int left_start = diff_chunk_get_left_start(c, r, context_lines);
 77 fe8af0d6 2020-10-06 stsp 	int left_end = diff_chunk_get_left_end(c, r, context_lines);
 78 fe8af0d6 2020-10-06 stsp 	int right_start = diff_chunk_get_right_start(c, r, context_lines);
 79 fe8af0d6 2020-10-06 stsp 	int right_end = diff_chunk_get_right_end(c, r,  context_lines);
 80 0d27172a 2020-05-06 neels 
 81 f374e913 2020-09-22 stsp 	*cc = (struct diff_chunk_context){
 82 3b0f3d61 2020-01-22 neels 		.chunk = {
 83 3b0f3d61 2020-01-22 neels 			.start = chunk_idx,
 84 3b0f3d61 2020-01-22 neels 			.end = chunk_idx + 1,
 85 3b0f3d61 2020-01-22 neels 		},
 86 3b0f3d61 2020-01-22 neels 		.left = {
 87 0d27172a 2020-05-06 neels 			.start = left_start,
 88 0d27172a 2020-05-06 neels 			.end = left_end,
 89 3b0f3d61 2020-01-22 neels 		},
 90 3b0f3d61 2020-01-22 neels 		.right = {
 91 0d27172a 2020-05-06 neels 			.start = right_start,
 92 0d27172a 2020-05-06 neels 			.end = right_end,
 93 3b0f3d61 2020-01-22 neels 		},
 94 3b0f3d61 2020-01-22 neels 	};
 95 3b0f3d61 2020-01-22 neels }
 96 3b0f3d61 2020-01-22 neels 
 97 61a7b578 2020-05-06 neels static bool
 98 f374e913 2020-09-22 stsp chunk_contexts_touch(const struct diff_chunk_context *cc,
 99 f374e913 2020-09-22 stsp 		     const struct diff_chunk_context *other)
100 3b0f3d61 2020-01-22 neels {
101 d362ea2e 2020-07-25 stsp 	return diff_ranges_touch(&cc->chunk, &other->chunk)
102 d362ea2e 2020-07-25 stsp 		|| diff_ranges_touch(&cc->left, &other->left)
103 d362ea2e 2020-07-25 stsp 		|| diff_ranges_touch(&cc->right, &other->right);
104 3b0f3d61 2020-01-22 neels }
105 3b0f3d61 2020-01-22 neels 
106 61a7b578 2020-05-06 neels static void
107 f374e913 2020-09-22 stsp chunk_contexts_merge(struct diff_chunk_context *cc,
108 f374e913 2020-09-22 stsp 		     const struct diff_chunk_context *other)
109 3b0f3d61 2020-01-22 neels {
110 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->chunk, &other->chunk);
111 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->left, &other->left);
112 d362ea2e 2020-07-25 stsp 	diff_ranges_merge(&cc->right, &other->right);
113 3b0f3d61 2020-01-22 neels }
114 3b0f3d61 2020-01-22 neels 
115 11caa5cc 2020-09-22 stsp struct diff_output_unidiff_state {
116 11caa5cc 2020-09-22 stsp 	bool header_printed;
117 11caa5cc 2020-09-22 stsp };
118 11caa5cc 2020-09-22 stsp 
119 11caa5cc 2020-09-22 stsp struct diff_output_unidiff_state *
120 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_alloc(void)
121 11caa5cc 2020-09-22 stsp {
122 11caa5cc 2020-09-22 stsp 	struct diff_output_unidiff_state *state;
123 11caa5cc 2020-09-22 stsp 
124 11caa5cc 2020-09-22 stsp 	state = calloc(1, sizeof(struct diff_output_unidiff_state));
125 11caa5cc 2020-09-22 stsp 	if (state != NULL)
126 11caa5cc 2020-09-22 stsp 		diff_output_unidiff_state_reset(state);
127 11caa5cc 2020-09-22 stsp 	return state;
128 11caa5cc 2020-09-22 stsp }
129 11caa5cc 2020-09-22 stsp 
130 f374e913 2020-09-22 stsp void
131 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_reset(struct diff_output_unidiff_state *state)
132 11caa5cc 2020-09-22 stsp {
133 11caa5cc 2020-09-22 stsp 	state->header_printed = false;
134 11caa5cc 2020-09-22 stsp }
135 11caa5cc 2020-09-22 stsp 
136 11caa5cc 2020-09-22 stsp void
137 11caa5cc 2020-09-22 stsp diff_output_unidiff_state_free(struct diff_output_unidiff_state *state)
138 11caa5cc 2020-09-22 stsp {
139 11caa5cc 2020-09-22 stsp 	free(state);
140 11caa5cc 2020-09-22 stsp }
141 11caa5cc 2020-09-22 stsp 
142 2c20a3ed 2020-09-22 stsp static int
143 2c20a3ed 2020-09-22 stsp output_unidiff_chunk(struct diff_output_info *outinfo, FILE *dest,
144 2c20a3ed 2020-09-22 stsp 		     struct diff_output_unidiff_state *state,
145 2c20a3ed 2020-09-22 stsp 		     const struct diff_input_info *info,
146 2c20a3ed 2020-09-22 stsp 		     const struct diff_result *result,
147 2c20a3ed 2020-09-22 stsp 		     const struct diff_chunk_context *cc)
148 3b0f3d61 2020-01-22 neels {
149 2c20a3ed 2020-09-22 stsp 	int rc;
150 ab528e22 2020-09-22 stsp 	off_t outoff = 0, *offp;
151 2c20a3ed 2020-09-22 stsp 
152 d362ea2e 2020-07-25 stsp 	if (diff_range_empty(&cc->left) && diff_range_empty(&cc->right))
153 2c20a3ed 2020-09-22 stsp 		return DIFF_RC_OK;
154 3b0f3d61 2020-01-22 neels 
155 2c20a3ed 2020-09-22 stsp 	if (outinfo && outinfo->line_offsets.len > 0) {
156 2c20a3ed 2020-09-22 stsp 		unsigned int idx = outinfo->line_offsets.len - 1;
157 2c20a3ed 2020-09-22 stsp 		outoff = outinfo->line_offsets.head[idx];
158 2c20a3ed 2020-09-22 stsp 	}
159 2c20a3ed 2020-09-22 stsp 
160 11caa5cc 2020-09-22 stsp 	if (!(state->header_printed)) {
161 2c20a3ed 2020-09-22 stsp 		rc = fprintf(dest, "--- %s\n", info->left_path ? : "a");
162 2c20a3ed 2020-09-22 stsp 		if (rc < 0)
163 2c20a3ed 2020-09-22 stsp 			return errno;
164 2c20a3ed 2020-09-22 stsp 		if (outinfo) {
165 2c20a3ed 2020-09-22 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
166 dabc1008 2020-09-22 stsp 			if (offp == NULL)
167 dabc1008 2020-09-22 stsp 				return ENOMEM;
168 2c20a3ed 2020-09-22 stsp 			outoff += rc;
169 2c20a3ed 2020-09-22 stsp 			*offp = outoff;
170 2c20a3ed 2020-09-22 stsp 
171 2c20a3ed 2020-09-22 stsp 		}
172 2c20a3ed 2020-09-22 stsp 		rc = fprintf(dest, "+++ %s\n", info->right_path ? : "b");
173 2c20a3ed 2020-09-22 stsp 		if (rc < 0)
174 2c20a3ed 2020-09-22 stsp 			return errno;
175 2c20a3ed 2020-09-22 stsp 		if (outinfo) {
176 2c20a3ed 2020-09-22 stsp 			ARRAYLIST_ADD(offp, outinfo->line_offsets);
177 dabc1008 2020-09-22 stsp 			if (offp == NULL)
178 dabc1008 2020-09-22 stsp 				return ENOMEM;
179 2c20a3ed 2020-09-22 stsp 			outoff += rc;
180 2c20a3ed 2020-09-22 stsp 			*offp = outoff;
181 2c20a3ed 2020-09-22 stsp 
182 2c20a3ed 2020-09-22 stsp 		}
183 11caa5cc 2020-09-22 stsp 		state->header_printed = true;
184 3b0f3d61 2020-01-22 neels 	}
185 3b0f3d61 2020-01-22 neels 
186 2c20a3ed 2020-09-22 stsp 	rc = fprintf(dest, "@@ -%d,%d +%d,%d @@\n",
187 3b0f3d61 2020-01-22 neels 		cc->left.start + 1, cc->left.end - cc->left.start,
188 3b0f3d61 2020-01-22 neels 		cc->right.start + 1, cc->right.end - cc->right.start);
189 2c20a3ed 2020-09-22 stsp 	if (rc < 0)
190 2c20a3ed 2020-09-22 stsp 		return errno;
191 2c20a3ed 2020-09-22 stsp 	if (outinfo) {
192 2c20a3ed 2020-09-22 stsp 		ARRAYLIST_ADD(offp, outinfo->line_offsets);
193 dabc1008 2020-09-22 stsp 		if (offp == NULL)
194 dabc1008 2020-09-22 stsp 			return ENOMEM;
195 2c20a3ed 2020-09-22 stsp 		outoff += rc;
196 2c20a3ed 2020-09-22 stsp 		*offp = outoff;
197 3b0f3d61 2020-01-22 neels 
198 2c20a3ed 2020-09-22 stsp 	}
199 2c20a3ed 2020-09-22 stsp 
200 0d27172a 2020-05-06 neels 	/* Got the absolute line numbers where to start printing, and the index
201 0d27172a 2020-05-06 neels 	 * of the interesting (non-context) chunk.
202 0d27172a 2020-05-06 neels 	 * To print context lines above the interesting chunk, nipping on the
203 0d27172a 2020-05-06 neels 	 * previous chunk index may be necessary.
204 0d27172a 2020-05-06 neels 	 * It is guaranteed to be only context lines where left == right, so it
205 0d27172a 2020-05-06 neels 	 * suffices to look on the left. */
206 0d27172a 2020-05-06 neels 	const struct diff_chunk *first_chunk;
207 0d27172a 2020-05-06 neels 	int chunk_start_line;
208 0d27172a 2020-05-06 neels 	first_chunk = &result->chunks.head[cc->chunk.start];
209 0d27172a 2020-05-06 neels 	chunk_start_line = diff_atom_root_idx(&result->left,
210 0d27172a 2020-05-06 neels 					      first_chunk->left_start);
211 2c20a3ed 2020-09-22 stsp 	if (cc->left.start < chunk_start_line) {
212 2c20a3ed 2020-09-22 stsp 		rc = diff_output_lines(outinfo, dest, " ",
213 0d27172a 2020-05-06 neels 				  &result->left.atoms.head[cc->left.start],
214 3b0f3d61 2020-01-22 neels 				  chunk_start_line - cc->left.start);
215 2c20a3ed 2020-09-22 stsp 		if (rc)
216 2c20a3ed 2020-09-22 stsp 			return rc;
217 2c20a3ed 2020-09-22 stsp 	}
218 3b0f3d61 2020-01-22 neels 
219 3b0f3d61 2020-01-22 neels 	/* Now write out all the joined chunks and contexts between them */
220 3b0f3d61 2020-01-22 neels 	int c_idx;
221 3b0f3d61 2020-01-22 neels 	for (c_idx = cc->chunk.start; c_idx < cc->chunk.end; c_idx++) {
222 3b0f3d61 2020-01-22 neels 		const struct diff_chunk *c = &result->chunks.head[c_idx];
223 3b0f3d61 2020-01-22 neels 
224 3b0f3d61 2020-01-22 neels 		if (c->left_count && c->right_count)
225 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
226 0d27172a 2020-05-06 neels 					  c->solved ? " " : "?",
227 0d27172a 2020-05-06 neels 					  c->left_start, c->left_count);
228 3b0f3d61 2020-01-22 neels 		else if (c->left_count && !c->right_count)
229 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
230 0d27172a 2020-05-06 neels 					  c->solved ? "-" : "?",
231 0d27172a 2020-05-06 neels 					  c->left_start, c->left_count);
232 3b0f3d61 2020-01-22 neels 		else if (c->right_count && !c->left_count)
233 2c20a3ed 2020-09-22 stsp 			rc = diff_output_lines(outinfo, dest,
234 0d27172a 2020-05-06 neels 					  c->solved ? "+" : "?",
235 0d27172a 2020-05-06 neels 					  c->right_start, c->right_count);
236 2c20a3ed 2020-09-22 stsp 		if (rc)
237 2c20a3ed 2020-09-22 stsp 			return rc;
238 3b0f3d61 2020-01-22 neels 	}
239 3b0f3d61 2020-01-22 neels 
240 3b0f3d61 2020-01-22 neels 	/* Trailing context? */
241 0d27172a 2020-05-06 neels 	const struct diff_chunk *last_chunk;
242 0d27172a 2020-05-06 neels 	int chunk_end_line;
243 0d27172a 2020-05-06 neels 	last_chunk = &result->chunks.head[cc->chunk.end - 1];
244 0d27172a 2020-05-06 neels 	chunk_end_line = diff_atom_root_idx(&result->left,
245 0d27172a 2020-05-06 neels 					    last_chunk->left_start
246 0d27172a 2020-05-06 neels 					    + last_chunk->left_count);
247 2c20a3ed 2020-09-22 stsp 	if (cc->left.end > chunk_end_line) {
248 2c20a3ed 2020-09-22 stsp 		rc = diff_output_lines(outinfo, dest, " ",
249 0d27172a 2020-05-06 neels 				  &result->left.atoms.head[chunk_end_line],
250 3b0f3d61 2020-01-22 neels 				  cc->left.end - chunk_end_line);
251 2c20a3ed 2020-09-22 stsp 		if (rc)
252 2c20a3ed 2020-09-22 stsp 			return rc;
253 2c20a3ed 2020-09-22 stsp 	}
254 2c20a3ed 2020-09-22 stsp 
255 2c20a3ed 2020-09-22 stsp 	return DIFF_RC_OK;
256 3b0f3d61 2020-01-22 neels }
257 3b0f3d61 2020-01-22 neels 
258 3e6cba3a 2020-08-13 stsp int
259 2c20a3ed 2020-09-22 stsp diff_output_unidiff_chunk(struct diff_output_info **output_info, FILE *dest,
260 2c20a3ed 2020-09-22 stsp 			  struct diff_output_unidiff_state *state,
261 2c20a3ed 2020-09-22 stsp 			  const struct diff_input_info *info,
262 2c20a3ed 2020-09-22 stsp 			  const struct diff_result *result,
263 2c20a3ed 2020-09-22 stsp 			  const struct diff_chunk_context *cc)
264 2c20a3ed 2020-09-22 stsp {
265 2c20a3ed 2020-09-22 stsp 	struct diff_output_info *outinfo = NULL;
266 2c20a3ed 2020-09-22 stsp 
267 2c20a3ed 2020-09-22 stsp 	if (output_info) {
268 2c20a3ed 2020-09-22 stsp 		*output_info = diff_output_info_alloc();
269 2c20a3ed 2020-09-22 stsp 		if (*output_info == NULL)
270 2c20a3ed 2020-09-22 stsp 			return ENOMEM;
271 2c20a3ed 2020-09-22 stsp 		outinfo = *output_info;
272 2c20a3ed 2020-09-22 stsp 	}
273 2c20a3ed 2020-09-22 stsp 
274 2c20a3ed 2020-09-22 stsp 	return output_unidiff_chunk(outinfo, dest, state, info,
275 2c20a3ed 2020-09-22 stsp 	    result, cc);
276 2c20a3ed 2020-09-22 stsp }
277 2c20a3ed 2020-09-22 stsp 
278 2c20a3ed 2020-09-22 stsp int
279 2c20a3ed 2020-09-22 stsp diff_output_unidiff(struct diff_output_info **output_info,
280 2c20a3ed 2020-09-22 stsp 		    FILE *dest, const struct diff_input_info *info,
281 0d27172a 2020-05-06 neels 		    const struct diff_result *result,
282 0d27172a 2020-05-06 neels 		    unsigned int context_lines)
283 3b0f3d61 2020-01-22 neels {
284 11caa5cc 2020-09-22 stsp 	struct diff_output_unidiff_state *state;
285 11caa5cc 2020-09-22 stsp 	struct diff_chunk_context cc = {};
286 2c20a3ed 2020-09-22 stsp 	struct diff_output_info *outinfo = NULL;
287 11caa5cc 2020-09-22 stsp 	int i;
288 11caa5cc 2020-09-22 stsp 
289 3b0f3d61 2020-01-22 neels 	if (!result)
290 3e6cba3a 2020-08-13 stsp 		return EINVAL;
291 3b0f3d61 2020-01-22 neels 	if (result->rc != DIFF_RC_OK)
292 3b0f3d61 2020-01-22 neels 		return result->rc;
293 3b0f3d61 2020-01-22 neels 
294 2c20a3ed 2020-09-22 stsp 	if (output_info) {
295 2c20a3ed 2020-09-22 stsp 		*output_info = diff_output_info_alloc();
296 2c20a3ed 2020-09-22 stsp 		if (*output_info == NULL)
297 2c20a3ed 2020-09-22 stsp 			return ENOMEM;
298 2c20a3ed 2020-09-22 stsp 		outinfo = *output_info;
299 2c20a3ed 2020-09-22 stsp 	}
300 2c20a3ed 2020-09-22 stsp 
301 11caa5cc 2020-09-22 stsp 	state = diff_output_unidiff_state_alloc();
302 2c20a3ed 2020-09-22 stsp 	if (state == NULL) {
303 2c20a3ed 2020-09-22 stsp 		if (output_info) {
304 2c20a3ed 2020-09-22 stsp 			diff_output_info_free(*output_info);
305 2c20a3ed 2020-09-22 stsp 			*output_info = NULL;
306 2c20a3ed 2020-09-22 stsp 		}
307 11caa5cc 2020-09-22 stsp 		return ENOMEM;
308 2c20a3ed 2020-09-22 stsp 	}
309 3b0f3d61 2020-01-22 neels 
310 2c20a3ed 2020-09-22 stsp 
311 3b0f3d61 2020-01-22 neels 	for (i = 0; i < result->chunks.len; i++) {
312 3b0f3d61 2020-01-22 neels 		struct diff_chunk *c = &result->chunks.head[i];
313 8546b045 2020-09-20 neels 		enum diff_chunk_type t = diff_chunk_type(c);
314 f374e913 2020-09-22 stsp 		struct diff_chunk_context next;
315 3b0f3d61 2020-01-22 neels 
316 9cc49695 2020-05-05 neels 		if (t != CHUNK_MINUS && t != CHUNK_PLUS)
317 9cc49695 2020-05-05 neels 			continue;
318 9cc49695 2020-05-05 neels 
319 9cc49695 2020-05-05 neels 		if (chunk_context_empty(&cc)) {
320 9cc49695 2020-05-05 neels 			/* These are the first lines being printed.
321 0d27172a 2020-05-06 neels 			 * Note down the start point, any number of subsequent
322 0d27172a 2020-05-06 neels 			 * chunks may be joined up to this unidiff chunk by
323 0d27172a 2020-05-06 neels 			 * context lines or by being directly adjacent. */
324 f374e913 2020-09-22 stsp 			diff_chunk_context_get(&cc, result, i, context_lines);
325 0d27172a 2020-05-06 neels 			debug("new chunk to be printed:"
326 0d27172a 2020-05-06 neels 			      " chunk %d-%d left %d-%d right %d-%d\n",
327 9cc49695 2020-05-05 neels 			      cc.chunk.start, cc.chunk.end,
328 9cc49695 2020-05-05 neels 			      cc.left.start, cc.left.end,
329 9cc49695 2020-05-05 neels 			      cc.right.start, cc.right.end);
330 9cc49695 2020-05-05 neels 			continue;
331 3b0f3d61 2020-01-22 neels 		}
332 3b0f3d61 2020-01-22 neels 
333 0d27172a 2020-05-06 neels 		/* There already is a previous chunk noted down for being
334 0d27172a 2020-05-06 neels 		 * printed. Does it join up with this one? */
335 f374e913 2020-09-22 stsp 		diff_chunk_context_get(&next, result, i, context_lines);
336 0d27172a 2020-05-06 neels 		debug("new chunk to be printed:"
337 0d27172a 2020-05-06 neels 		      " chunk %d-%d left %d-%d right %d-%d\n",
338 9cc49695 2020-05-05 neels 		      next.chunk.start, next.chunk.end,
339 9cc49695 2020-05-05 neels 		      next.left.start, next.left.end,
340 9cc49695 2020-05-05 neels 		      next.right.start, next.right.end);
341 9cc49695 2020-05-05 neels 
342 9cc49695 2020-05-05 neels 		if (chunk_contexts_touch(&cc, &next)) {
343 0d27172a 2020-05-06 neels 			/* This next context touches or overlaps the previous
344 0d27172a 2020-05-06 neels 			 * one, join. */
345 9cc49695 2020-05-05 neels 			chunk_contexts_merge(&cc, &next);
346 0d27172a 2020-05-06 neels 			debug("new chunk to be printed touches previous chunk,"
347 0d27172a 2020-05-06 neels 			      " now: left %d-%d right %d-%d\n",
348 9cc49695 2020-05-05 neels 			      cc.left.start, cc.left.end,
349 9cc49695 2020-05-05 neels 			      cc.right.start, cc.right.end);
350 9cc49695 2020-05-05 neels 			continue;
351 9cc49695 2020-05-05 neels 		}
352 9cc49695 2020-05-05 neels 
353 0d27172a 2020-05-06 neels 		/* No touching, so the previous context is complete with a gap
354 0d27172a 2020-05-06 neels 		 * between it and this next one. Print the previous one and
355 0d27172a 2020-05-06 neels 		 * start fresh here. */
356 0d27172a 2020-05-06 neels 		debug("new chunk to be printed does not touch previous chunk;"
357 0d27172a 2020-05-06 neels 		      " print left %d-%d right %d-%d\n",
358 9cc49695 2020-05-05 neels 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
359 2c20a3ed 2020-09-22 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result, &cc);
360 9cc49695 2020-05-05 neels 		cc = next;
361 9cc49695 2020-05-05 neels 		debug("new unprinted chunk is left %d-%d right %d-%d\n",
362 9cc49695 2020-05-05 neels 		      cc.left.start, cc.left.end, cc.right.start, cc.right.end);
363 3b0f3d61 2020-01-22 neels 	}
364 3b0f3d61 2020-01-22 neels 
365 3b0f3d61 2020-01-22 neels 	if (!chunk_context_empty(&cc))
366 2c20a3ed 2020-09-22 stsp 		output_unidiff_chunk(outinfo, dest, state, info, result, &cc);
367 11caa5cc 2020-09-22 stsp 	diff_output_unidiff_state_free(state);
368 3b0f3d61 2020-01-22 neels 	return DIFF_RC_OK;
369 3b0f3d61 2020-01-22 neels }