106 # back far enough unless we also look at the a and b as candidates. |
106 # back far enough unless we also look at the a and b as candidates. |
107 # This only occurs when a is a descendent of b or visa-versa. |
107 # This only occurs when a is a descendent of b or visa-versa. |
108 return min(limit, a, b) |
108 return min(limit, a, b) |
109 |
109 |
110 def _chain(src, dst, a, b): |
110 def _chain(src, dst, a, b): |
111 """chain two sets of copies a->b""" |
111 """chain two sets of copies 'a' and 'b'""" |
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112 |
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113 # When chaining copies in 'a' (from 'src' via some other commit 'mid') with |
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114 # copies in 'b' (from 'mid' to 'dst'), we can get the different cases in the |
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115 # following table (not including trivial cases). For example, case 2 is |
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116 # where a file existed in 'src' and remained under that name in 'mid' and |
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117 # then was renamed between 'mid' and 'dst'. |
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118 # |
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119 # case src mid dst result |
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120 # 1 x y - - |
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121 # 2 x y y x->y |
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122 # 3 x y x - |
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123 # 4 x y z x->z |
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124 # 5 - x y - |
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125 # 6 x x y x->y |
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126 |
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127 # Initialize result ('t') from 'a'. This catches cases 1 & 2. We'll remove |
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128 # case 1 later. We'll also catch cases 3 & 4 here. Case 4 will be |
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129 # overwritten later, and case 3 will be removed later. |
112 t = a.copy() |
130 t = a.copy() |
113 for k, v in b.iteritems(): |
131 for k, v in b.iteritems(): |
114 if v in t: |
132 if v in t: |
115 # found a chain |
133 # found a chain, i.e. cases 3 & 4. |
116 if t[v] != k: |
134 if t[v] != k: |
117 # file wasn't renamed back to itself |
135 # file wasn't renamed back to itself (i.e. case 4, not 3) |
118 t[k] = t[v] |
136 t[k] = t[v] |
119 if v not in dst: |
137 if v not in dst: |
120 # chain was a rename, not a copy |
138 # chain was a rename, not a copy |
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139 # this deletes the copy for 'y' in case 4 |
121 del t[v] |
140 del t[v] |
122 if v in src: |
141 if v in src: |
123 # file is a copy of an existing file |
142 # file is a copy of an existing file, i.e. case 6. |
124 t[k] = v |
143 t[k] = v |
125 |
144 |
126 for k, v in list(t.items()): |
145 for k, v in list(t.items()): |
127 # remove criss-crossed copies |
146 # remove criss-crossed copies, i.e. case 3 |
128 if k in src and v in dst: |
147 if k in src and v in dst: |
129 del t[k] |
148 del t[k] |
130 # remove copies to files that were then removed |
149 # remove copies to files that were then removed, i.e. case 1 |
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150 # and file 'y' in cases 3 & 4 (in case of rename) |
131 elif k not in dst: |
151 elif k not in dst: |
132 del t[k] |
152 del t[k] |
133 |
153 |
134 return t |
154 return t |
135 |
155 |