Start field can be disambiguation.

README.md

@@ -44,8 +44,8 @@ converted to UTC for easier comparison.
 **Application** and **library versions** can be seen in an application, using `version` command. \
 The latest versions are:
 
-Application: 0.0.1.414:846+20231120.192246 <!--- readme-new-app-version-major-minor-feature-commit+meta~breaks-place-marker --> \
-Library: 0.0.1.414:846+20231120.192246 <!--- readme-new-lib-version-major-minor-feature-commit+meta~breaks-place-marker -->
+Application: 0.0.1.415:847+20231120.200002 <!--- readme-new-app-version-major-minor-feature-commit+meta~breaks-place-marker --> \
+Library: 0.0.1.415:847+20231120.200002 <!--- readme-new-lib-version-major-minor-feature-commit+meta~breaks-place-marker -->
 
 Versioning used is [Natural Versioning 1.2](https://croatian-chess.blogspot.com/p/natver.html),
 with meta data containing the same format as the book version.

ws/crochess/src/crochess.c

@@ -26,7 +26,7 @@
 #include "crochess.h"
 
 
-char const CROCHESS_VERSION[] = "0.0.1.414:846+20231120.192246"; // source-new-crochess-version-major-minor-feature-commit+meta~breaks-place-marker
+char const CROCHESS_VERSION[] = "0.0.1.415:847+20231120.200002"; // source-new-crochess-version-major-minor-feature-commit+meta~breaks-place-marker
 
 #ifdef __WITH_LINE_NOISE__
 char const CROCHESS_HISTORY_FILE_NAME[] = "history_crochess.txt";

ws/libcrochess/inc/cc_chessboard.h

@@ -139,6 +139,17 @@ bool cc_chessboard_is_coord_on_board( CcChessboard * restrict cb, int coord );
 */
 bool cc_chessboard_is_pos_on_board( CcChessboard * restrict cb, int i, int j );
 
+/**
+    Function returning if at least one coordinate of given disambiguation belongs to a board.
+
+    @param cb Chessboard.
+    @param i File, position along horizontal axis.
+    @param j Rank, position along vertical axis.
+
+    @return `true` if disambiguation is on-board, `false` otherwise.
+*/
+bool cc_chessboard_is_disambiguation_on_board( CcChessboard * restrict cb, int i, int j );
+
 /**
     Function checks if given coordinate is within safe off-board boundaries.
 
@@ -168,6 +179,21 @@ bool cc_chessboard_is_coord_safe_off_board( CcChessboard * restrict cb, int coor
 */
 bool cc_chessboard_is_pos_safe_off_board( CcChessboard * restrict cb, int i, int j );
 
+/**
+    Function returning if at least one coordinate of given disambiguation is within safe off-board boundaries.
+
+    @param cb Chessboard.
+    @param i File, position along horizontal axis.
+    @param j Rank, position along vertical axis.
+
+    @note
+    Coordinate is safely off-board if there could be a movement (e.g. trance-journey),
+    which would place piece back on-board.
+
+    @return `true` if disambiguation is safe off-board, `false` otherwise.
+*/
+bool cc_chessboard_is_disambiguation_safe_off_board( CcChessboard * restrict cb, int i, int j );
+
 /**
     Function returning if given position is on a light side of board.
 

ws/libcrochess/src/cc_chessboard.c

@@ -150,6 +150,11 @@ bool cc_chessboard_is_pos_on_board( CcChessboard * restrict cb, int i, int j ) {
     return CC_IS_POS_ON_BOARD( cb->size, i, j );
 }
 
+bool cc_chessboard_is_disambiguation_on_board( CcChessboard * restrict cb, int i, int j ) {
+    if ( !cc_chessboard_is_size_valid( cb ) ) return false;
+    return CC_IS_COORD_ON_BOARD( cb->size, i ) || CC_IS_COORD_ON_BOARD( cb->size, j );
+}
+
 bool cc_chessboard_is_coord_safe_off_board( CcChessboard * restrict cb, int coord ) {
     if ( !cc_chessboard_is_size_valid( cb ) ) return false;
 
@@ -167,6 +172,15 @@ bool cc_chessboard_is_pos_safe_off_board( CcChessboard * restrict cb, int i, int
              ( (int)(-diag) <= j ) && ( j <= (int)( cb->size + diag ) ) );
 }
 
+bool cc_chessboard_is_disambiguation_safe_off_board( CcChessboard * restrict cb, int i, int j ) {
+    if ( !cc_chessboard_is_size_valid( cb ) ) return false;
+
+    size_t diag = cc_diagonal( cb->size );
+
+    return ( ( ( (int)(-diag) <= i ) && ( i <= (int)( cb->size + diag ) ) ) || \
+             ( ( (int)(-diag) <= j ) && ( j <= (int)( cb->size + diag ) ) ) );
+}
+
 bool cc_chessboard_is_field_on_light_side( CcChessboard * restrict cb, int j ) {
     if ( !cc_chessboard_is_size_valid( cb ) ) return false;
     return CC_IS_FIELD_ON_LIGHT_SIDE( cb->size, j );

ws/libcrochess/src/cc_path_gens.c

@@ -48,7 +48,7 @@ CcPathLink * cc_find_paths_all_pieces__new( CcChessboard * restrict cb,
     if ( CC_PIECE_IS_NONE( piece ) ) return NULL;
     if ( CC_PIECE_IS_WAVE( piece ) && CC_PIECE_IS_NONE( activator ) ) return NULL;
 
-    bool is_start_on_board = cc_chessboard_is_pos_on_board( cb, start__d.i, start__d.j );
+    bool is_start_on_board = cc_chessboard_is_disambiguation_on_board( cb, start__d.i, start__d.j );
     bool is_end_on_board = cc_chessboard_is_pos_on_board( cb, end__d.i, end__d.j );
 
     if ( !is_start_on_board && !is_end_on_board ) return NULL; // <1>

ws/libcrochess/src/cc_version.c

@@ -11,4 +11,4 @@
 */
 
 
-char const CC_LIB_VERSION[] = "0.0.1.414:846+20231120.192246"; // source-new-libcrochess-version-major-minor-feature-commit+meta~breaks-place-marker
+char const CC_LIB_VERSION[] = "0.0.1.415:847+20231120.200002"; // source-new-libcrochess-version-major-minor-feature-commit+meta~breaks-place-marker

ws/tests/src/tests.c

@@ -34,7 +34,7 @@
 #include "tests.h"
 
 
-char const CROCHESS_TESTS_VERSION[] = "0.0.1.414:846+20231120.192246"; // source-new-crochess-tests-version-major-minor-feature-commit+meta~breaks-place-marker
+char const CROCHESS_TESTS_VERSION[] = "0.0.1.415:847+20231120.200002"; // source-new-crochess-tests-version-major-minor-feature-commit+meta~breaks-place-marker
 
 #ifdef __WITH_LINE_NOISE__
 char const CROCHESS_TESTS_HISTORY_FILE_NAME[] = "history_tests.txt";